According to the environmental sensitivity’s meta-framework, humans have a survival function of processing information, which allows an adaptation to contexts [1
]. This makes individuals differ in their sensitivity to environmental influences with some being more or less affected by negative and positive exposures [2
]. Regarding the scientific literature, it has provided research related to the variability in environmental sensitivity [2
]. In fact, according to researchers’ proposals, three main theories have been developed to describe what entails sensitivity in humans [3
]. The first one is the Sensory Processing Sensitivity (SPS) theory, which is based on a personality perspective [6
]. SPS has been presented as a manifestation of environmental sensitivity, and people characterized by a high level of this trait are referred to as highly sensitive [2
]. Moreover, Aron [8
] distinguishes four aspects of high sensitivity: (a) great awareness of subtleties, (b) overstimulation, (c) depth of information processing, and (d) high emotional reactivity [9
]. Furthermore, as claimed by Aron [3
], it is estimated that about 30% of the society can present a high manifestation of SPS [11
]. This theory also suggests that SPS is a relatively stable personality trait that is shaped from childhood to adulthood while individuals interact with the environment [2
Additionally, in relation to a genetic framework, Belsky [4
] has proposed the Differential Susceptibility Theory (DST), which highlights that environmental sensitivity has been defined as a continuum that represents an individual’s sensitivity not only to both negative and positive external environment influences, but also to internal stimuli, for better and for worse, in relation to the perception to respond to situational demands [2
]. In this regard, high SPS could be manifested as a greater reactivity to environmental stimuli [1
]. Additionally, on the other hand, as stated by Boyce and Ellis [5
] in their Biological Sensitivity to Context (BSC) theory, humans present a neurobiological predisposition, suggesting that the environment affects individuals who are physiologically highly reactive [2
]. Thus, given the relevant contribution of these three frameworks, researchers agreed that sensitive individuals differ in their responses to both adverse and supportive aspects of the environment [2
As recent research has further concluded, the construct of environmental sensitivity appears to be formed by a variety of dimensions, instead of referring to it simply as the sensitivity toward sensory stimuli, considering a one-factor structure [7
]. Some studies, which have applied scales for assessing environmental sensitivity, have pointed out the presence of three factors [1
]: (1) the Low Sensory Threshold (LST), which reflects an unpleasant sensory arousal to external and internal stimuli; (2) Ease of Excitation (EOE), which indicates that people with high sensitivity could be easily overwhelmed by external and internal demands; and (3) Aesthetic Sensitivity (AES), which refers to the aesthetic awareness, by noticing subtleties in the environment. Other authors demonstrated the multidimensionality that environmental sensitivity likely shows, establishing different factor structures composed of two, three and four dimensions in psychometric studies in Europe, Asia and Central America [16
]. Nevertheless, to date, only Weyn et al. [17
] have reported cross-cultural comparisons of environmental sensitivity between the U.K. and Belgium young children.
Regarding the measurement of environmental sensitivity across genders and ages, previous results indicated minor differences between females and males, presenting girls and early adolescents with a significantly higher level of sensitivity than boys and late adolescents [17
]. However, these studies were only conducted with children and adolescents from the U.K., so more research is needed to ensure that these results are interpretated in the same way [1
Thus, the Highly Sensitive Child Scale (HSCS) was developed based on the assumptions of the meta-framework for the concept of environmental sensitivity, especially its creation from the personality perspective of the SPS theory [2
]. The HSCS includes 12 items in which important aspects of environmental sensitivity are captured [1
]. In fact, a parent-report format in the HSCS is available to assess environmental sensitivity of children in kindergarten and primary education. For this purpose, items were altered and questions rephrased in such a way that parents referred to the behavior they observed in their child. In this sense, Pluess et al. [1
] investigated the factorial structure of the original HSC scale, reflecting a bifactorial model. This structure suggests that both the total sensitivity score and the three specific dimensions are important to measure environmental sensitivity [1
]. Moreover, recent studies show that the HSC scale presents adequate psychometric properties, considering reliability, convergent validity, and factor analysis in several methodological studies [1
In addition, translations of the HSP and HSC scales were carried out using a large number of languages [7
]; Dutch, Italian, German, Turkish, Japanese and Icelandic versions are available with adequate psychometric properties [17
]. In Spain, Chacón et al. [16
] validated the first instrument to assess environment sensitivity in adults. In this study, the structure of the questionnaire resulted in no changes in the items, adopting the highest level of linguistic, cultural and conceptual equivalence with the original questionnaire [16
]. However, the factor structure and psychometric properties of the HSC scale have not yet been tested in Spanish children.
To date, most researchers agree that environmental sensitivity presents difficulties in its identification [25
]. Some research studies reported many sensitivity factors as markers of environmental sensitivity (such as cortisol reactivity, negative emotionality or the 5-HTTLPR gene) [26
]. In fact, it is suggested that the HSC scale could be a more reliable marker of environmental sensitivity than other traditional susceptibility factors, such as temperament [17
]. However, to date, it is difficult to describe the hypothesis in which the phenotypic trait of environmental sensitivity is directly represented [1
]. Therefore, brief and easily applied assessment tools in various contexts can facilitate early detection and intensity in several areas (e.g., the school environment, mental health centers, or family contexts).
Several studies found that HSC scale plays a role of prediction in treatment response to a universal school-based resilience promoting intervention, with children reaching benefits when scoring highly in the HSC [17
]. Health and quality of life implications of sensory processing sensitivity on children’s lives highlight the need to promote early identification, since it could surely refer to effects in the evolutive development of youngsters. Brief and easily applied assessment tools in several contexts can ease the detection of high levels of SPS due to the lack of instruments to evaluate this phenotypic trait of environmental sensitivity. Moreover, the applicability of this instrument may provide us with essential information about how environmental sensitivity is manifested in our cultural context.
The present pilot study aims to conduct a transcultural adaptation of the Spanish version of the Highly Sensitive Child Scale and to analyze the psychometric properties of this instrument in Spanish children. To attain this goal, the HSC scale factor structure, internal consistency, and convergent validity of the Spanish version are examined.
Previous research studies showed evidence in relation to the differences among children in their environmental sensitivity, with some being more sensitive to both negative and positive environmental contexts and internal stimuli [2
]. Providing accurate assessment instruments can ease the detection of the level of SPS in children, in order to find out the characteristics of the personality trait and its health and social implications [11
]. This study aimed to carry out a transcultural adaptation of the Highly Sensitive Child Scale and analyze its psychometric properties in a sample of Spanish children. The results reveal the good fit of the bifactor model proposed by Pluess et al. [1
]. Moreover, this article revealed the satisfactory fit of the three-factor structure model and evidence of adequate internal consistency and convergent validity for the Spanish version of the HSC scale.
Following Pluess et al. [1
] and Weyn et al. [17
], the fit of the bifactor model, with a general sensitivity factor and a three-factor structure, was tested. The Spanish version of the HSC scale showed the adequate fit of the bifactor model. This bifactor structure model of the HSC scale suggests that both the general sensitivity score and the three subscale scores are essential to measure environmental sensitivity in Spanish children. These results are consistent with the findings of Pluess et al. [1
]. Moreover, the three-factor structure obtained good fit indices in the Spanish sample through the CFA. Despite the fact that the only well-adjusted model was the one that presented a three-factor structure, different internal consistency indices of the Spanish version of the HSC scale indicated that the total score and its three dimensions had an acceptable-to-good reliability. These results are in line with the findings of these authors, both as a general sensitivity factor and as a three-factor structure [1
] (Table 5
Regarding the convergent validity, the distinction among the subscales was observed in the association between the Aesthetic Sensitivity and EAS dimensions, and the correlations between the other HSC scale dimensions and temperament dimensions. These associations indicated that high levels of SPS and its domains were positively associated with a higher rate of temperament and emotionality, assessed through the parent-report EAS scale. Additionally, greater AES was associated with higher sociability and lower shyness in the evaluated children. According to Belsky and Pluess [14
], environmental sensitivity seems to be related to both approaching behaviors towards positive environments, and withdrawal behaviors towards negative ones. This finding appears to be in line with the idea that individuals scoring a high SPS can be more sensitive to both positive and negative environmental stimuli [14
Additionally, based on these results, it seems that Aesthetic Sensitivity reflects another aspect of environmental sensitivity in the Spanish sample. AES may show a sensitivity towards positive experiences than Ease of Excitation and Low Sensory Threshold, confirming that these latter two domains are more similar [51
Concerning the comprehension of environmental sensitivity, according to Chawla [52
], albeit cultural interpretations change among people and places, it seems Spanish parents could have a similar understanding due to the fact that the structure of the HSC scale and its items are maintained with respect to the original one [1
]. Additionally, a minor difference was found between males and females on the AES, presenting higher scores for females. This finding is also consistent with the findings of other authors, since it appears that environmental sensitivity tends to differ between sex groups; however, these differences are not significant [1
]. Moreover, the age of children also seems to indicate a relationship with environmental sensitivity. Our results show that primary education children are more likely to present high levels of environmental sensitivity, especially in the EOE, AES and HSC total score. Indeed, Pluess et al. [1
] also found positive correlations between age and environmental sensitivity.
This study also has its limitations. First, the sample was quite small, which could make the results difficult to generalize. Additionally, the moderate and low correlations which provide evidence of convergent validity with this sample must be considered when interpretating the results. These correlations should therefore be interpreted with caution, since EAS is not a sensory processing sensitivity measure. As a matter of fact, although hetero-informed questionnaires tend towards social desirability and provide some bias in the results, the 12-item HSC scale was adapted for use as a parent-rated measure of the children’s sensitivity [1
]. Furthermore, the parent-report HSC measure demonstrated a power of prediction of externalizing problems in children [1
]. However, more future research studies are needed to analyze the factorial invariance to find out the influence of gender and age, and if the measurement properties are independent of these variables. Moreover, invariance analysis should be conducted to test the interpretation of environmental sensitivity across gender and age groups [17
]. In addition, the Spanish HSC scale could present difficulties to determine the level of sensitivity in children, since the assessment of sensory processing sensitivity could be made more objective with cognitive, genetic or physiological markers [7
On the other hand, the present study is the first investigation of the Spanish parent-version of the HSC scale as a measure of environmental sensitivity in children. This paper also adds new evidence about the usefulness of the HSC scale for the assessment of sensory processing sensitivity in children. Increasingly more countries [7
] are currently validating this instrument for different cultures, revealing adequate psychometric properties and factorial support. Indeed, the findings of this research are characterized by a sophisticated psychometric approach that provides a gold standard instrument for the assessment of environmental sensitivity. Therefore, the present study offers to the scientific community a transcultural adaptation of a highly reliable tool, which allows for the identification of the sensory processing sensitivity trait.