Promoting Conservation Intentions Through Humanized Messaging in Green Advertisements: The Mediation Roles of Empathy and Responsibility

Abstract

Plastic waste accumulation is a pressing environmental challenge that demands interdisciplinary solutions. This study investigated whether humanized messaging in green advertisements increases consumers’ conservation intentions. Grounded in self-expansion theory and dual-process theory, we propose a serial mediation model that integrates affective (empathy) and cognitive (perceived responsibility) pathways to explain conservation behavior in humanized environmental campaigns. We conducted a scenario-based experiment (N = 505) to test these mechanisms. Green ads that humanize marine animals significantly increased empathy, perceived responsibility, and conservation intentions. Moreover, the effect of humanized messaging on conservation intentions was sequentially mediated by heightened empathy, which in turn strengthened perceived responsibility. As a pioneering study aiming to propose and empirically test the affective–cognitive pathway, our work provides novel insights into how emotional and rational processes jointly shape environmental decision-making. The findings advance theory on consumers’ conservation behavior and provide actionable guidance for enterprises and policymakers to design evidence-based initiatives for plastic waste reduction.

1. Introduction

Plastic pollution presents a severe threat to marine ecosystems, the global climate, and human health. An estimated 75 to 199 million tons of plastic waste currently linger in the oceans, with more than 10 million additional tons entering each year [1,2]. These pollutants endanger marine life through various pathways: sea turtles often suffocate from being entangled in discarded fishing nets, and seabirds lose their ability to feed due to plastic debris filling their stomachs [3]. Moreover, microplastics have permeated the marine food chain, potentially entering the human circulatory system through seafood consumption [4]. Plastics generate greenhouse gas emissions throughout their entire life cycle, leading to potential climate risks [5]. To tackle these crises, policymakers must go beyond pre-production measures (e.g., alternative materials) and post-consumption solutions (e.g., proper waste disposal). Implementing targeted regulations and promoting public advocacy to influence consumer plastic use are critical [1,2].

Environmental agencies face a significant communication challenge: conservation messages, such as promoting reusable shopping bags or recycling plastic bottles, often feel too abstract. Although plastic pollution increasingly harms marine ecosystems, the spatial disconnect between this issue and the daily lives of land-dwelling residents makes it seem distant and less urgent. As a result, people’s sense of responsibility for environmental problems diminishes, along with their motivation to take pro-environmental actions [2]. Anthropomorphism, as a well-established strategy in advertising, attributes human features, motivations, intentions, and emotions to non-human entities [6]. In line with the self-expansion theory, this approach helps audiences perceive environmental problems more concretely and reduces the psychological distance between individuals and environmental issues or their sources [7,8]. In environmental marketing research, scholars have primarily focused on natural elements such as the Earth, water resources, and rivers—entities without inherent life-like characteristics—to examine the effects of humanized portrayals on pro-environmental behavior [9,10,11]. The findings suggest that humanizing these natural objects encourages individuals to perceive them similarly to humans, thereby fostering pro-environmental actions [12]. However, the effectiveness of anthropomorphism in promoting pro-environmental attitudes varies by animal species as people often project human-like expectations onto animals depicted with such traits [13,14]. When a humanized animal fails to meet these expectations, it can elicit feelings of antipathy or even hostility [14,15]. Despite the frequent use of sea creatures in environmental campaigns to highlight marine plastic pollution, there is limited empirical evidence supporting the efficacy of humanized messaging in enhancing environmental communication.

This study aims to validate the effectiveness of humanized messaging by examining the serial mediation mechanism through affective and cognitive pathways in pro-environmental advertising. A central debate in the academic literature is whether humanized strategies drive pro-environmental behavior through emotional arousal or cognitive change [16]. Ahn, Kim and Aggarwal [9] found that humanized trash cans can elicit guilt and encourage individuals to sort their garbage. In contrast, the cognitive viewpoint underscores the role of anthropomorphism in reconfiguring the cognitive accessibility of natural concepts. For instance, Zhu, Wong and Huang [8] discovered that humanized rivers can foster conservation behavior by reducing social psychological distance and stimulating perceived responsibilities.

Building on the dual-process theory, this study proposes a novel explanatory mechanism that integrates affective and cognitive pathways through empathy and perceived responsibility. In contrast to prior research that primarily focuses on singular mediators like guilt and sympathy [9,12], this study highlights a dynamic psychological process. When the spokespersons in environmental advertisements are animals with greater biological similarity to humans [17,18], they foster an empathic connection (“I can feel their pain”), evoke a sense of responsibility (“I should help them”), and ultimately promote conservation intentions. This mechanism also demonstrates why a more proactive emotion—empathy—is required in green advertisements using animals as spokespersons to explain the effects of human-like communication on conservation behaviors [17]. This differs from previous studies utilizing non-living environmental symbols like a humanized version of Earth or rivers, which employed passive emotional mechanisms such as guilt [9] or sympathy [12].

This study uses a scenario-based experimental approach to address two research objectives: validating the effectiveness of humanized messaging in enhancing environmental communication and examining the serial mediation mechanism involving empathy and perceived responsibility. The findings will offer evidence-based policy recommendations to help governmental agencies and enterprises design targeted plastic waste reduction initiatives.

2. Theoretical Background and Hypothesis Development

2.1. Green Ads Utilizing Humanized Messaging

Anthropomorphism involves attributing human-like external characteristics, motivations, intentions, and emotions to non-human entities [19]. This cognitive process promotes comprehending and interpreting the behavior patterns of non-human entities [20]. The perceptual fluency effect resulting from this mentalization process can enhance cognitive pleasure and information processing efficiency [21]. Consequently, marketers utilize humanized figures like Ronald McDonald and Hatsune Miku to improve consumer engagement and message effectiveness [6,22,23]. Nonetheless, humanized communication strategies may elicit adverse consumer responses [22,24]. Consumers aiming to maintain social distance actively avoid anthropomorphized brands to minimize interpersonal interactions [25]. When consumers perceive humanized entities as rivals or obstacles to their personal objectives, self-protective mechanisms can be triggered [22].

The effectiveness of human-like communication in environmental research is inconsistent as well [16]. While many studies suggest that advertisements featuring humanized non-living entities, such as the Earth [26] and water resources [11], can enhance pro-environmental behaviors [16], the results are not uniform. Anthropomorphism encourages individuals to perceive nature’s experiences and vulnerabilities in the face of destructive human actions, thereby fostering conservation efforts [8]. Animals with inherent human-like biological features (e.g., sensory organs such as a mouth and eyes) can be humanized, and the mental state attributed to animals allows them to be moral agents worthy of care and concern and to exert normative social influence on observers; however, these animals are also endorsed with the perceived capability of being responsible for their potential intentional actions [20]. Thus, while evidence supports the effectiveness of anthropomorphism in promoting conservation behavior, research also indicates that not all types of humanized animals consistently inspire conservation efforts [14,15,27]. For example, Japanese tourists at monkey feeding parks feel upset when monkeys fight over food, perceiving this behavior as rude and a violation of feeding interaction norms, as they associate feeding animals with Japanese gift-giving traditions [27]. The humanization of one species may lead people to develop negative social stereotypes about those animals, potentially harming conservation efforts [14]. This complex perception of humanized animals creates ambiguity in the effectiveness of such messaging, highlighting the need to determine whether the use of humanized sea creatures in green advertisements can effectively encourage conservation behavior.

The effect of plastic pollution on the marine ecosystem is largely a result of human consumption and the usage patterns of plastic products rather than the actions or behaviors of sea creatures. This study suggests that utilizing humanized messaging in environmental campaigns can improve individuals’ awareness of marine plastic pollution and encourage conservation intention.

2.2. Self-Expansion Theory and Dual-Process Theory

2.2.1. Self-Expansion Theory

The self-expansion theory proposed by Aron and Aron [28] posits that individuals are fundamentally motivated to expand themselves by acquiring new resources, perspectives, and identities. This process involves incorporating external entities (such as people, groups, or ideas) into one’s self-concept, thereby broadening self-boundaries and enhancing goal achievement [29]. Initially, the theory was applied to explain altruistic behaviors in intimate relationships. When individuals integrate others into their sense of self, helping others is perceived as “helping the expanded self,” which motivates proactive assistance [30]. Subsequent research extended the theory beyond romantic relationships. For example, it was found that in social comparison scenarios, incorporating others into an individual’s self-boundaries mitigates negative self-evaluation when others outperform them [31]. Studies in marketing have shown that consumers often perceive brands as means for self-expansion [32,33].

In environmental contexts, self-expansion theory has been adapted to frame the perceived overlap between self and nature, referred to as the inclusion of nature in self (INS) [34]. This perspective views the self, others, and nature as interconnected. Schultz operationalized INS using a single pictorial item featuring seven “me”–“nature” circle pairs, ranging from fully separate to nearly overlapping. However, single-item measures lack reliability testing [35]. As research progressed, broader indicators of people’s connection to nature were adopted, such as the new ecological paradigm [36], implicit association tests [35] and, particularly, the Connectedness to Nature Scale [37], which is now a widely used measure of self-expansion toward nature.

In studies involving the anthropomorphism of nature, connectedness to nature functions as an affective measure of self-expansion and consistently increases when nature is humanized. For instance, portraying nature as feminine [38] or giving Earth a human-like facial expression [39] strengthens humans’ connectedness to nature, which in turn fosters environmental concern and promotes pro-environmental intentions. In short, anthropomorphism enhances self-expansion, with connectedness to nature serving as a key measure in this context [37,38,39]. Building on this body of research, the present study explores how humanized communication involving marine animals fosters viewers’ self-expansion toward nature. This, in turn, may enhance their empathy and inspire conservation behaviors [29,40].

2.2.2. Dual-Process Theory

This study applies self-expansion theory to examine the influence of humanized environmental advertisements on conservation behaviors. It introduces an innovative serial mediation model grounded in dual-process theory [41,42], which explains how Type 1 and Type 2 processing mechanisms interact to shape behavioral outcomes.

Dual-process theory distinguishes between two modes of information processing: Type 1 and Type 2. The former is automatic, fast, unconscious, and experiential, while the latter is slower, deliberate, and supports logical reasoning and hypothetical thinking [43]. Depending on the context, these modes can work either in conflict or synergy to influence decision-making and behavior [42]. Anthropomorphism assigns human qualities to nature, reducing perceived differences and psychological distance [7] while integrating nature into the self and strengthening self–nature connectedness [38,39]. When individuals encounter humanized messages featuring distress appeals from marine creatures, this self-expansion fosters perspective-taking, allowing them to experience the environmental struggles of natural entities as their own, thereby eliciting empathy [37,40,44].

Dual-process theory explains how this kind of empathy translates into intention. Initially, the empathy triggered by humanized messaging arises through Type 1 processing—an unconscious, automatic, and rapid affective response. This is followed by Type 2 processing, which reflectively evaluates and integrates the emotion, reconstructs causal links between the suffering of marine creatures and human actions, and cultivates a sense of responsibility. This sense of responsibility acts as a psychological mediator, bridging environmental dilemmas with behavioral decisions. Type 2 processing integrates the affective output of Type 1 processing into logical reasoning, forming an “affect-driven, cognitively reconstructed” pathway that converts empathy into conservation intentions (see Figure 1 for an overview of the theoretical framework).

2.3. Empathy and Perceived Responsibility

Empathy plays a crucial role in shaping environmental attitudes [40,45]. Its impact manifests in four key dimensions: (1) adopting others’ viewpoints; (2) demonstrating compassion during others’ hardships; (3) sharing others’ personal suffering experiences; and (4) empathizing with fictional characters. This emotional capacity serves as a vital motivator for altruistic behaviors, encompassing emotions like sympathy, care, and tenderness [40,46,47]. However, distinguished from sympathy, empathy involves not only recognizing others’ needs but also actively immersing oneself in others’ experiences to comprehend the impact of their circumstances from their perspectives [45,48]. Perceived responsibility refers to a felt obligation to safeguard others’ welfare, including the natural environment [49]. Prior research has identified it as a robust predictor of prosocial and pro-environmental behavior: when people perceive greater responsibility for environmental protection, they are more likely to act accordingly [8,50,51,52]. Consumers who attribute environmental problems to human activity report higher perceived responsibility and greater pro-environmental attention [50]. A stronger sense of responsibility prioritizes environmental benefits and increases the likelihood of adopting pro-environmental behavior [51].

Current research on anthropomorphism in pro-environmental studies continues to explore the roles of mediators. For example, Ketron and Naletelich [12] proposed that sympathy explains the impact of humanized nature on sustainable consumption. Meanwhile, Jiang, Feng, Zhou, Yang and Su [7] emphasized a shortened social psychological distance as the foundation for emotions like sympathy and guilt toward anthropomorphized animals. Zhu, Wong and Huang [8] further demonstrated that reducing social psychological distance enhances perceived responsibility, thereby influencing conservation behaviors.

Unlike previous studies that focused on single-dimensional mediation mechanisms, this research draws on dual-process theory to introduce a serial mediation model that integrates both emotional and cognitive pathways. This framework offers a fresh perspective on the dynamics of anthropomorphism strategies in pro-environmental communication. Specifically, humanized messaging in green ads elicits emotional resonance (i.e., empathy) toward the animals being portrayed, which subsequently strengthens perceived responsibility, ultimately driving conservation intentions. This serial mediation model bridges the gap between emotion-driven theories (e.g., guilt as a mediator; Ahn, Kim and Aggarwal [9]) and cognition-driven models (e.g., psychological distance reduction; Zhu, Wong and Huang [8]) by demonstrating their interconnected roles in a sequential process.

Anthropomorphized communication enhances people’s perceived connection with nature, leading individuals to integrate ecological environments into their psychological boundaries [38,39]. The self-expansion theory posits that the expansion of self-boundaries strengthens empathy and altruistic tendencies by blurring the cognitive distinction between “self” and “others” [29,46,47]. This self-expansion mechanism has been proven to significantly promote pro-environmental behaviors [34,37]. When nature is perceived as an “extended self,” individuals exhibit stronger ecological responsibility and conservation actions [44,53].

Moreover, compared to sympathy—a static emotional projection toward the current state of the sufferer—empathy constitutes dynamic emotional resonance that helps an individual actively understand the sufferer’s experiences [54]. We posit that people do not consider themselves to be of the same kind as plants or rivers even if they are humanized. However, animals’ possession of sensory organs (e.g., eyes and mouths) and autonomous mobility endow them with significant similarities to humans [17,18]. Consequently, humanized messaging may strengthen people’s perceived connection with sea creatures, fostering an in-group perception. In line with the two information processing modes suggested by the dual-process theory [41,42,43], unlike the static sympathy projected toward anthropomorphized plants [12], humanized sea creatures are likely to trigger dynamic empathy [17,40,55]. Such emotional resonance can promote self-reflection on personal behaviors, stimulate perceived responsibility, and enhance conservation intention (see Figure 1). Thus, we propose the following hypotheses:

H1. 

Green ads featuring sea creatures with humanized messaging (vs. non-humanized messaging) result in stronger (H1a) empathy, (H1b) perceived responsibility, and (H1c) conservation intention.

H2. 

The superior impact of humanized messaging in green ads on conservation intention is sequentially mediated by empathy and perceived responsibility.

Figure 1 illustrates the theoretical framework of this study.

3. Research Design and Methodology

3.1. Pretest: Advertisement Stimulus

Previous studies have explored anthropomorphism in two primary forms: visual representations and textual descriptions. Visual anthropomorphism involves adding human-like physical traits, such as clothing or facial and hand-like features [9,24]. In contrast, textual anthropomorphism attributes psychological traits, such as a consciousness and emotions, to non-human entities using techniques like first-person narratives [38,56]. In this study, to emphasize the urgency of improving marine habitats, we employed text-based humanized messaging in green advertisements while preserving the authentic imagery of marine ecosystems and creatures.

We designed an environmental campaign titled “Reduce & Recycle” as the context for the green ads and selected a real image of a sea turtle with a plastic bag over its head as the visual basis for the experimental stimulus. Anthropomorphism was implemented through textual descriptions. In the humanized messaging condition, the sea turtle adopted a first-person narrative to promote participation, while the non-humanized messaging scenario conveyed the environmental appeal from a third-party perspective (see Appendix A for an overview of the full text). Consequently, we generated two experimental stimulus images (see Figure 2).

Volunteers for the pretest were recruited via the online data platform Credamo. A total of 62 participants were randomly assigned to view one of the two stimulus images (humanized messaging/non-humanized messaging). Participants spent three minutes examining the green ads and reading the accompanying text before scoring five 7-point Likert scale items measuring anthropomorphism (e.g., “To what extent does the sea turtle in the image possess its own emotional experiences/free will/consciousness/intentions/minds?”, rated from 1 (“not at all”) to 7 (“very much”); α = 0.89; [7]).

The pretest results revealed the effectiveness of the stimulus images in manipulating anthropomorphism (M_humanized = 5.413, M_{non-humanized} = 2.974, t (60) = −15.953, p < 0.001). Therefore, they were used in the main experiment.

3.2. Main Study

3.2.1. Participants and Procedures

A single-factor between-subjects experimental design was implemented in the formal study. A total of 508 volunteers were recruited from the online platform Credamo. The volunteers were randomly assigned to two groups of stimulus pictures selected during the pretest. They were instructed to view the green ad and read the text on it for three minutes. Three of the participants failed the attention test questions [57]; therefore, the final effective sample size was 505 (47.90% female; mean age = 38.77).

Then, the participants scored three items measuring conservation intention (e.g., “How likely are you to take part in the Reduce & Recycle campaign?” with a score ranging from 1 (“highly unlikely”) to 7 (“highly likely”); α = 0.814; [58]); five items measuring empathy (e.g., “I feel compassionate toward the sea turtle”, rated from 1 (“strongly disagree”) to 7 (“strongly agree”); α = 0.785; [8]); and four items measuring perceived responsibility (e.g., “It is my responsibility to provide aid for the sea turtle”, rated from 1 (“strongly disagree”) to 7 (“strongly agree”); α = 0.716; [49]) (see Appendix B for an overview of the measurement items). They also completed the same five-item scale used in the pretest to measure anthropomorphism [7], with two questions assessing the authenticity of the scenario [59] and two questions addressing confounding variables: plastic pollution concern (“How concerned are you about plastic pollution?” rated from 1 (“not at all concerned”) to 7 (“extremely concerned”)) and attitude toward marine animals (“Overall, how favorable or unfavorable is your attitude toward marine animals?” rated from 1 (“very unfavorable”) to 7 (“very favorable”)). Finally, the participants provided demographic information, such as gender and age (see

Table 1. Demographic characteristics of participants (N = 505).

Demographic Variable	Frequency	Percentage
Gender
Male	263	52.10%
Female	242	47.90%
Age
18–30 years	149	29.50%
31–45 years	189	37.43%
46–60 years	167	33.07%
Education level
Below high school	126	24.95%
Junior college	140	27.72%
Bachelor’s degree	169	33.47%
Master’s degree and above	70	13.86%
Occupation
Students	116	22.97%
State-owned enterprises or public servant	139	27.52%
Private enterprise staff	151	29.91%
Freelance	99	19.60%

).

3.2.2. Results

Manipulation checks. An independent samples t-test confirmed the successful manipulation of anthropomorphism through the experimental materials. Participants exposed to humanized messaging scored significantly higher (M = 5.348) than those exposed to non-humanized messaging (M = 2.878), with a highly significant difference (t (480.27) = −53.10, p < 0.001). Tests for confounding variables showed no significant differences in the participants’ plastic pollution concern (p = 0.212) or attitude toward marine animals (p = 0.638), ruling out their influence on conservation intention.

Additionally, scenario realism was consistently rated highly across both groups. The average score (M = 5.515) was significantly above the scale midpoint of 4 (t (504) = 35.862, p < 0.001). To address potential common method bias, Harman’s single-factor test was conducted. An exploratory factor analysis of all substantive measures identified three distinct components, with the first unrotated factor accounting for 44.86% of the variance (below the 50% threshold), indicating that common method bias does not significantly affect the results [60].

Independent samples t-test. We coded the green ad type (the independent variable X) as follows: 0 = non-humanized messaging; 1 = humanized messaging. The results of the independent samples t-test on conservation intention demonstrated that participants under the humanized condition showed significantly stronger conservation intention compared to those under the non-humanized condition (M_humanized = 5.843, M_{non-humanized} = 5.241, t (375.57) = −8.342, p < 0.001). Further independent sample t-tests on empathy and perceived responsibility revealed similar findings: participants under the anthropomorphic condition exhibited higher perceived empathy (M_humanized = 5.175, M_{non-humanized} = 4.825, t (446.78) = −7.912, p < 0.001) and stronger perceived responsibility (M_humanized = 4.775, M_{non-humanized} = 4.515, t (382.02) = −4.804, p < 0.001) (see

Table 2. Results of independent sample t-tests: effect of green ad types (N = 505).

Green ad Types (X)		Mean	SD	t	df	p
0	Empathy (M1)	4.825	0.580	−7.912	446.781	< 0.001
1		5.175	0.398
0	Responsibility (M2)	4.516	0.767	−4.804	382.021	< 0.001
1		4.778	0.404
0	Conservation (Y)	5.241	1.021	−8.342	375.573	< 0.001
1		5.843	0.522

Note: For green ad types (X): non-humanized messaging = 0; humanized messaging = 1. Responsibility refers to perceived responsibility. Conservation refers to conservation intention.

and Figure 3). These results are consistent with Hypothesis 1, which states that green ads using humanized messaging (vs. non-humanized messaging) lead to stronger (H_1a) empathy, (H_1b) perceived responsibility, and (H_1c) conservation intention.

Serial mediation effects. To investigate the main impact of green ad types through serial mediation from empathy to perceived responsibility, we conducted an indirect effect analysis of serial mediation using PROCESS Model 6 [61]. We coded green ad types as the independent variable (X: 0 = non-humanized messaging; 1 = humanized messaging), with conservation intention as the dependent variable (Y), empathy as the first mediator (M₁), and perceived responsibility as the second mediator (M₂). Bootstrap analysis revealed that humanized messaging through empathy and perceived responsibility had a statistically significant sequential indirect effect on conservation intention compared to non-humanized messaging (β = 0.261, SE = 0.042, 95% CI [0.182, 0.344]). Additionally, the direct effect of humanized messaging on conservation intention was significant (β = 0.357, SE = 0.060, 95% CI [0.238, 0.475]), indicating a partial sequential mediation pathway, but neither the indirect effect mediated through merely empathy (95% CI [−0.003, 0.145]) nor through perceived responsibility (95% CI [−0.103, 0.026]) was significant (see Figure 4 and

Table 3. Results of conceptual model. Panel B: Total, direct, and indirect effects of ad type on conservation intention.

Panel A:		Empathy (M1)					Perceived Responsibility (M2)
Antecedent		Coeff.	SE	t	p		Coeff.	SE	t	p
Constant	iM1	4.825	0.031	154.230	<0.001	iM2	0.243	0.187	1.304	0.193
Green ad type (X)	a1	0.350	0.044	7.906	<0.001	a2	−0.048	0.040	−1.193	0.234
Empathy (M1)						d21	0.886	0.038	23.138	<0.001
R2		0.111					0.537
		F (1, 503) = 62.505, p < 0.001					F (2, 502) = 291.425, p < 0.001
		Conservation Intention (Y)
Antecedent		Coeff.	SE	t	p
Constant	iy	1.207	0.279	4.334	<0.001
Green ad type (X)	c’	0.357	0.060	5.928	<0.001
Empathy (M1)	b1	0.156	0.082	1.903	0.058
Responsibility (M2)	b2	0.727	0.067	10.928	<0.001
R2		0.461
		F (3, 501) = 142.924, p < 0.001
Panel B:
			Effect		BootSE		BootLLCI		BootULCI
Total effect of X on Y     c			0.601		0.072		0.460		0.743
R2					0.121
					F (1, 503) = 69.434, p < 0.001
Direct effect of X on Y     c′			0.357		0.060		0.238		0.475
Total indirect effect			0.283		0.054		0.179		0.392
Ind1 (X→ M1→ Y)			0.063		0.038		−0.003		0.145
Ind2 (X→ M1→ Y)			−0.040		0.033		−0.103		0.026
Ind3 (X→ M1→ M2-→ Y)			0.261		0.042		0.182		0.344

Note: For green ad types (X): non-humanized messaging = 0; humanized messaging = 1. Responsibility refers to perceived responsibility. For indirect effect(s): Ind1 refers to indirect effect through empathy. Ind2 refers to indirect effect through perceived responsibility. Ind3 refers to indirect effect through empathy and perceived responsibility sequentially.

). These results confirm that humanized messaging promotes conservation intention through the sequential enhancement of empathy and consequent perceived responsibility, thereby supporting H2. To further explore evidence for the sequential mediation effect, we tested a reversed pathway in which humanized messaging first enhanced perceived responsibility, which subsequently increased empathy. However, a bootstrapping analysis indicated that this alternative sequential indirect effect was not significant (95% CI = [−0.003, 0.063]). This finding reinforces the hypothesized relationship we proposed, emphasizing that perceived responsibility originates from empathy and serves as a key driver of conservation intention.

4. General Discussion and Implications

4.1. Theoretical Implications

This study examined the impact of humanized messaging in green advertisements on consumers’ conservation intentions, focusing on the underlying psychological mechanisms—a dimension largely overlooked in prior research. While previous studies have typically explored either a single cognitive mediator [8] or a single affective mediator [12,38,39] to explain conservation behaviors, this research leveraged self-expansion theory and dual-process theory to propose and evaluate a serial mediation mechanism. The model integrates empathy (affective) and perceived responsibility (cognitive) to provide a more comprehensive understanding of the drivers behind conservation behaviors. This is the first study to reveal the combined effect of an affective–cognitive pathway within the context of environmental communication.

In addition, in the manipulation of anthropomorphism, different from the stimuli commonly used in previous studies, such as the Earth and natural water resources [11,26,38], we selected a real sea creature as the basis for the experimental stimuli and achieved anthropomorphism manipulation through textual descriptions [21,62]. By examining this real sea creature stimulus and the serial mediation process, we gained a more comprehensive understanding of the promoting effect of anthropomorphism strategies on conservation intention in green ads involving sea creatures and the underlying mechanism.

This study introduces a novel approach, namely a serial mediation mechanism involving empathy and perceived responsibility in sequence, to explain the effect of anthropomorphism on conservation intention. Previous studies have separately focused on the roles of affective and cognitive pathways in explaining anthropomorphism-driven conservation behaviors. While some scholars highlight the importance of core affective factors, such as sympathy and guilt [9,12], others have demonstrated the independent influence of cognitive elements, such as social psychological distance [8]. Although scholars have noted the potential sequential impact of cognitive factors and emotional feelings on conservation behaviors [7], empirical research on serial mediation mechanisms has not been conducted. Based on self-expansion theory and dual-process theory, this study developed a serial mediation model integrating both affective and cognitive mediators. Through a scenario-based experimental study, it reveals for the first time that humanized messaging activates empathy, subsequently triggers perceived responsibility, and ultimately influences conservation intention —a mechanism that unifies previously fragmented psychological explanations.

Our research extends the theoretical scope of self-expansion theory and dual-process theory into the domain of environmental marketing—a field in which these theoretical constructs have received limited scholarly attention. We examine consumers’ reactions toward the humanized environmental campaign and reveal its underlying psychological mechanism. The findings support the hypothesis that participants first develop emotional resonance (empathy) toward humanized sea creatures, which then reshapes their cognition (perceived responsibility) and translates into behavioral intentions.

The present study takes a different approach from previous environmental research, which has often relied on humanized stimuli lacking life-like characteristics, such as the Earth, trees, and water resources [11,12,38,39]. Instead, we chose animals with greater biological similarity to humans [18] as our experimental stimuli. This approach is based on the premise that the species proximity of humanized objects plays a critical role in activating empathy mechanisms [17]. Unlike abstract natural entities (e.g., trees or the earth), marine creatures—animals with a central nervous system—share a deeper basis for empathy with humans [18]. This cross-species emotional connection mechanism aligns with the mirror neuron theory, which posits that observing the suffering of fellow vertebrates is more likely to activate empathic neural circuits in humans [17]. Additionally, as the ultimate destination for plastic pollution [1,2], the marine ecosystem serves as a visually concrete and accessible backdrop for illustrating scenarios of biological harm. Compared to abstract representations like Mother Earth, the use of real sea creatures in humanized messaging more vividly conveys the tangible consequences of ecological damage, thereby increasing people’s willingness to participate in environmental campaigns.

4.2. Managerial Implications

This study offers valuable insights into optimizing environmental communication strategies. It recommends incorporating the serial mediation mechanism of emotional arousal (e.g., empathy) and cognitive change in the design of green advertisements, with a particular emphasis on selecting humanized subjects. The findings suggest a strategic approach to enhancing environmental messaging by prioritizing animals with biological similarities to humans. Unlike traditional abstract symbols, such as Earth or forests, sea creatures impacted by plastic pollution—like sea turtles and whales—are more effective at engaging observers’ cognitive responses. This is due to their human-like central nervous systems and identifiable facial features, which evoke stronger emotional and cognitive connections [40]. Marine ecosystems serve as vivid proof of plastic pollution’s devastating effects, a narrative often highlighted in media coverage. To amplify ecological urgency, organizations could document marine animals’ survival struggles through authentic imagery in documentaries and social media content. However, ethics and communication efficacy must be balanced. Simulated or remotely filmed content should be prioritized to avoid causing secondary harm to animals during production. For effective dissemination, the intensity of distressing imagery should be controlled to prevent empathy desensitization, and positive narratives like rescue cases should be integrated to maintain emotional resonance.

Secondly, this study confirms that empathy can stimulate perceived responsibility. Therefore, mass media should first establish emotional empathy between audiences and nature and then activate people’s perceived responsibility and conservation intention. For example, humanized narratives—such as designing “first-person” monologs for marine life or using virtual reality to simulate the sensory experiences of animals affected by pollution—can effectively evoke emotional resonance. A successful example of this theory in practice is BBC Earth’s documentary series Blue Planet II [63]. Furthermore, when promoting corporate environmental initiatives, enterprises can utilize humanized elements to enhance consumer empathy and recognition of their sustainability philosophies. This approach facilitates public perception of the organization’s social responsibility commitments, potentially transferring consumers’ endorsement of ecological principles to broader corporate affinity.

The literature often generalizes the measurement of private and public environmental behaviors, encompassing broad categories such as water usage, electricity consumption, and personal transportation. This broad approach complicates the analysis of decision-making mechanisms for specific pro-environmental behaviors, making it challenging to gain nuanced insights [64]. Some studies, such as that by Do, Wang and Guchait [26], have measured targeted pro-environmental behaviors (e.g., reusing hotel towels or purchasing unattractive vegetables) through scenario-based experimental studies. Research on green advertising has largely overlooked the critical issue of plastic pollution control. This study sought to fill that gap through a scenario-based experimental approach. By designing targeted promotional scenarios for plastic reduction campaigns, it investigated the impact of anthropomorphism on participation in such initiatives. The findings suggest practical strategies and provide behavioral prediction indicators to support environmental policymaking.

4.3. Limitations and Future Research Directions

This study advances the environmental communication literature on anthropomorphism; however, several limitations remain and must be addressed in future work. First, this study only compared the effects of humanized and non-humanized messaging on conservation intention. Anthropomorphism can take diverse forms, such as “Mother River,” “Child River” [8], “Father Earth,” “Mother Earth” [38], “Smiling Earth,” and “Crying Earth” [12]. Those forms can be manipulated through textual descriptions (e.g., “All the people in this area are my children” vs. “All the people in this area are my parents”) or visual cues (e.g., smiling vs. crying faces), as demonstrated in previous studies [8,12]. Prior research indicates that textual anthropomorphism affects conservation intentions through cognitive pathways [8], whereas visual anthropomorphism may operate through affective pathways [12]. Both forms may also foster pro-environmental behavior through shared mechanisms such as connectedness to nature [38,39]. Future studies should investigate whether the proposed serial mediation model generalizes across different forms of anthropomorphism.

Second, the boundary conditions of the serial mediation model warrant examination. Individual differences may moderate the observed effects [16]. For example, power states primed through imagined scenarios can shape outcomes [65]. While humanized messaging may heighten emotion, it might also elicit defensive reactions (e.g., attentional avoidance and dissociation), thereby weakening the mediation effect. Conversely, higher power states may facilitate the translation of empathy into conservation intention via the sequential mediation pathway. Furthermore, perceived responsibility may further moderate the empathy–intention link. According to the norm activation model [66], perceived responsibility activates moral norms, thereby strengthening the translation of empathy into conservation intention; low perceived responsibility may attenuate this effect. Investigating these boundary conditions would clarify the underlying psychological processes.

Third, this study employs a sea turtle as the focal animal in the environmental message, which may limit the generalizability of the findings due to potential species-specific effects [14]. Future research should replicate the study using a variety of animals (e.g., seabirds and seals) to assess robustness. Additionally, the current research focuses exclusively on plastic pollution; thus, the results may not extend to other environmental issues (e.g., habitat loss and air pollution) without further investigation. Finally, conservation intention was measured through self-reported surveys, which may be subject to common method bias [60]. Incorporating objective behavioral indicators (e.g., actual sign-up rates for environmental campaigns) in future studies would help to address this limitation [67].

5. Conclusions

In conclusion, this study uncovered a serial mediation mechanism in which humanized messaging evokes empathy, which in turn fosters perceived responsibility and strengthens consumers’ conservation intentions. This theoretical framework offers evidence-based insights for governmental agencies and enterprises to design targeted plastic waste reduction initiatives, contributing to efforts to mitigate the growing environmental impacts of plastic pollution.