1. Introduction
In a classification of time experiences at least three aspects can be discerned: (1) the time perspective of past, present, and future; (2) time estimation as measured by the accuracy in estimating clock time; and (3) time awareness as the subjective impression of time passing relatively fast or slow. Conceptually, it has repeatedly been argued that these three dimensions are interrelated.
To highlight one line of research, it has been shown that a more pronounced present perspective at the expense of the future perspective is associated with an inability to delay gratification,
i.e., individuals select choices with smaller but sooner rewards over those with larger but later rewards [
1,
2]. For most people the subjective value of future rewards decreases considerably with longer waiting time. Impulsive individuals have an even stronger “temporal myopia”,
i.e., only what is located within a shortened temporal horizon of the present moment is relevant [
3]. That is, impulsive individuals who are present oriented are not as able to wait through a period of time as they act more on the spur of the moment—behaviour which in the long run can have negative consequences [
4].
In order to explain this behaviour it has been suggested that a stronger focus on the momentary passage of time in more present-oriented, impulsive individuals would lead to a relative overestimation of duration (time estimation) and the feeling that time is passing more slowly (time awareness). The feeling of having to wait too long would consequently lead to short-sighted decision-making [
5,
6]. Individuals with psychiatric syndromes who are highly impulsive indeed overestimate duration in the seconds-to-minutes range [
7,
8]. In a different line of research experimentally induced social exclusion led to a less pronounced future perspective in individuals and a relative overestimation of temporal intervals of 40 and 80 s duration [
9].
Ideally we flexibly switch the time perspective, either focusing on the past from the standpoint of the psychological present or imaging the future from the present perspective to create alternative goal states [
10]. An impulsive state would mean that one would be stuck in the present moment at the expense of the future perspective [
4]. Standing in contrast to the impulsive present perspective, another form of present-perspective is achieved through meditation techniques where individuals learn to focus on the present moment without being distracted by upcoming external stimuli and thoughts. Importantly, one has to differentiate between an impulsive present perspective and present-mindedness as trained through meditation practice [
11]: the former is associated with a strong urge to act in the present moment and is stimulus-oriented, whereas the latter is associated with an observational state associated with more self-control [
12]. It has recently been shown that meditation-naïve and meditation-experienced persons after a short mindfulness meditation relatively overestimate duration in the milliseconds-to-seconds range [
13,
14]. Moreover, students scoring higher on self-reported mindfulness were more accurate in their timing abilities in the milliseconds and multiple-seconds range [
12] In a cross-sectional study with experienced mindfulness meditators and matched controls no differences in the timing of short duration (time estimation) was found but meditators experienced less time pressure, more time dilation, and a general slower passage of time (time awareness) [
15].
The reported connections between the time dimensions, especially between the present-perspective and time estimation/time awareness, however, are rather unsystematic. For example, there are only few studies showing a direct relationship between a psychometrically validated measure of the time perspective such as the Zimbardo Time Perspective Inventory (ZTPI) [
16] and measures of time estimation or time awareness. The ZTPI assesses individual characteristics on five dimensions of the time perspective, namely the past-negative, past-positive, present-hedonistic, present-fatalistic, and future. One cross-sectional study directly showed that a greater future perspective in the ZTPI correlated with longer duration reproductions in the seconds’ range [
17]. In another study, time estimation in the seconds’ range was weakly correlated with the time perspective, where the younger subject group (ages between 15 and 25) was more accurate in time estimation and had a more pronounced present-perspective; the older group (ages between 35 and 55) had a more pronounced future perspective [
18]. In one further study the everyday experiences of more or less punctuality in life did not strikingly relate to judgments of short duration [
19]. Regarding the scarcity of research or a lack of reported direct relationships between the three aspects of time, we wanted to compare the individual time perspective with the subjective awareness of the passage of time. A second aim was to assess the awareness of passing time across age groups. The feeling that time speeds up as we grow older is an impression most people report [
20,
21,
22]. However, only in recent years it has been shown that—at least for populations in industrialized nations—the subjective speed of the passage of time, especially the passage of the last 10 years, indeed speeds up with increasing age [
23,
24,
25]. Interestingly, it is the retrospectively judged time interval of the last 10 years and not the last year, the last month or week that is sensitive for age differences [
26].
Retrospective judgements of time are thought to rely on memory processes,
i.e., the more contextual changes have been stored in memory the longer duration seems in retrospect [
27,
28]. An increasing subjective speed of the passage of time when we get older could be explained through the amount of contextual changes stored in episodic memory over that time span; that is, when we get older, due to the fact that we become more experienced and have more routines in life, the novelty of life events diminishes and these events are stored in memory with less emotional strength [
22]. This intuitive notion however still has to be proven empirically and there is some debate about the validity and the underlying factors contributing to this widely held notion [
20,
26,
29].
With our study we aim to assess the typically experienced passage of time over longer intervals; thus we are investigating retrospective judgements of subjective time (time awareness). Perception of duration in the seconds-to-minutes range (time estimation) is thought to be governed by specific time keeping systems activated when one is prospectively judging duration,
i.e., during a short time interval which one is experiencing at present [
27]. In studies on prospective time perception in the multiple-second range results point to age-related differences that are attributable to decreased attention regulation capacity with increasing age [
30].
To these two ends, (1) the potential relationship between the time perspective and time awareness; and (2) the question of factors influencing the subjective passage of time over the life span, we conducted an online survey. Regarding the time perspective we employed the ZTPI [
16] and additionally used the factor “presence” of the Freiburg Mindfulness Inventory (FMI) [
31] as measure of the “holistic presence” time perspective [
32]; for the recent development of a positive presence scale, the present-eudaimonic scale, see [
33]). That is, the ZTPI contains the hedonistic and fatalistic present perspective, but a different form of presence related to the mindful awareness of the present moment is an additional form of present perspective, especially interesting for the study of subjective time [
11,
34,
35]. In addition, we employed a “balanced time perspective” as calculated from the five dimensions of the ZTPI [
36,
37]. Regarding typical time awareness in everyday life, questions regarding “time pressure”, “time expansion/boredom”, “routines in life”, and “how the passage of time typically passes” were posed [
23]. Moreover, to address the question of age-related differences concerning the subjective passage of time over past time intervals of the last week, month, year, and ten years, additional questionnaires were employed, namely the scales for experiencing emotions (SEE) [
38,
39], a short form of the five factor personality inventory NEO-FFI (BFI-K; Big Five Inventory—Kurzform [
40]) of the five factor personality inventory (the NEO-FFI), and the Barratt Impulsiveness Scale (BIS-11) [
41]. Strong emotions in healthy individuals such as with trait-anxiety lead to a slower passage of felt time [
42]; impulsive individuals more often overestimate duration and complain that time passes too slowly [
5]. Relating to the two open questions mentioned above we aimed at conducting this exploratory study: (1) associating for the first time inventories relating to the time perspective with measures of time awareness; and (2) investigating potential factors related to age-related differences in retrospective judgments of various life spans.
4. Discussion
The two study parts assessing: (1) influences of the individual time perspective on time awareness and (2) psychological factors influencing the perception of the passage of time over the last ten years revealed the following results:
The mindful-oriented present perspective of the FMI correlated moderately and positively with the ZTPI subscales of hedonistic presence and the past positive perspective; there is a negative association between the mindful-present perspective and the past negative perspective. The holistic presence thereafter is associated with enjoying being and acting in the here and now as well as looking back into the past with positive feelings. Also with increasing age participants have a stronger mindful present-perspective. With one exception, the dimensions of the time perspective did not relate to the retrospective judgments of past intervals; individuals who are more present-hedonistic felt a faster passage of the last week. Age, as repeatedly found, was a predictor of the perception of the passage of time over the last ten years: the older participants the faster time passed by. Several effects between the dimensions of the time perspective and everyday experience of time were detected: a faster speed of the passage of time was predicted by a more pronounced future perspective; a pronounced past negative perspective is related to more time pressure, time expansion/boredom, and the feeling of more routine in life; past negative feelings thus are overall related to negative impressions of the passage of time. Fitting into the overall picture, being a more present-perspective hedonist is related to having less routine in life. With increasing age participants experienced less time pressure and less time expansion/boredom,
i.e., they have generally more positive feelings about time. However, when inspecting age-group differences descriptively (
Table A4), less time expansion/boredom is mostly experienced between the ages of 30 and 59 years, the life span when individuals are most committed to work; decreased time pressure is most pronounced when people are 60 years and older,
i.e., when they are more likely retired (for similar results, see [
23]).
What are factors influencing the retrospective passage of time over the last 10 years, the time interval of our lives that speeds up as we get older? It is the ability to regulate emotions and a more balanced time perspective which is associated with a slower passage of this time span. Relating to everyday time experiences, feeling time pressure and a general faster passage of time are both related to the retrospective faster passage of the last ten years.
The experience of time can be inter-individually characterized. The personal pattern of how the time perspective is represented influences—as we show here—everyday experience of the subjective passage of time. Individuals with a stronger future perspective have the feeling that time passes typically more quickly. The relation between the future perspective and a faster subjective passage of time is understandable in the context of models of time perception. Subjective time emerges through the perception of the self across time as an enduring and embodied entity [
48,
49]: as has empirically been shown, intertwined affective and interoceptive states of the body create our experience of duration [
50,
51]. Moreover, an increased awareness of oneself and the surrounding world coincides with an increased awareness of time over longer intervals in retrospect—leading to the feeling that time passes more slowly [
52]. Although in our study we did not find a relationship between the holistic present perspective and the typical passage of time (though a more mindful present-perspective is related to less time pressure), a more pronounced future perspective at the expense of the present perspective thereafter would lead to a general faster passage of subjective time.
The past negative perspective is overall related to a negative sense of time, that is, to the opposed feelings of more time pressure and to more boredom. Following Zimbardo and Boyd [
32] (p. 88), in their description of this perspective, the attitudes about past events, which matter more than the events themselves, are “key to the development of gratitude, which allows you to appreciate your life in the present.” Positive attitudes towards the past are also related to greater satisfaction with present life. Emotional distress, in contrast, is related to alterations in subjective time, namely to both extreme situations where time passes too slowly or when there is not enough time [
42,
53,
54]. Conforming to earlier studies on successful aging [
55], people with increasing age do not become more past oriented. To the contrary, as we show in our sample with individuals with an upper age range of 81, age is actually negatively related to both the negative and the positive past perspective; in accordance with this positive appraisal of aging effects, older subjects have a stronger present perspective.
Our results confirm previous studies showing that the retrospectively judged time interval of the past 10 years and not the last year, the last month or week is associated with age. With increasing age individuals feel that time is passing more quickly [
23,
24,
25]. Memory-related explanations pertaining to routine and to the loss of novelty of events as we become older have theoretically been postulated [
22]. The fact that experiencing more routine in life is linked to a faster passage of the last decade in our study additionally validates this claim; routine has been shown to speed up subjective time [
28]. Here we show how emotions—strongly linked to memory encoding and retrieval [
45] as well as to memory for duration [
56]—are predictive of the feeling of the passage of the last ten years. Merely being exposed to more emotions, such as registered by many subscales of the inventory for experiencing emotions (SEE), does not lead to a slower passage of time of the past ten years.It is the subscale of emotional self-regulation that leads to a slower passage of subjective time over this time interval. What these results point to, regarding the memory-load model of retrospective time, is that the mere passive feelings of emotions themselves are not sufficient to encode and retrieve more efficiently memory contents—and thus expand subjective time. It is the competence to voluntarily and actively regulate mood states and emotional reactions. As shown in another validation study, the capacity of emotion regulation is negatively correlated with neuroticism, stress, depression, and trait-anxiety and positively correlated with life satisfaction; moreover, it is positively linked to general problem solving, self-esteem, and the amount of social contacts, among other variables [
39]. That is, emotion regulation is a proxy for having variable coping strategies, emotional and instrumental, as well as for the sense of self-efficacy. This form of emotional and social intelligence thus is a means to feel a subjective slower passage over the last ten years. Individuals who feel a faster passage of the past decade also feel more time pressure and a generally faster speed of the passage of time. According to our results, emotionally competent individuals have the propensity to expand their subjective life time.
Another factor that leads to a slower passage of the last 10 years is having a balanced time perspective, meaning that an individual loads high on the past positive time perspective, has moderately high scores on the future and the present hedonistic time perspective, and shows low scores on the past negative and the present fatalistic time perspective [
32,
36]. Moreover, a balanced time perspective, which is age-independent, is correlated with more mindfulness, less impulsivity, a better handling of emotions, and with more positive personality traits (friendliness and less neuroticism). A person who is more balanced in his or her time perspective is future orientated but can also savor the moment and can positively learn from the past. Our empirical findings strongly speak in favor of the idea that a balanced time perspective is an indication of individual happiness and health [
32]—let alone the existential fact that for individuals with a balanced time perspective life time passes more slowly.
Limitations of this study are the education and age bias in the study sample. That is, a large proportion of subjects were comparably highly educated and young, a bias which is typically seen in academic studies capitalizing on easy access to the student population. However, our results on retrospective judgments of duration are very similar to outcomes of former studies having a more balanced age and education sample. Therefore, we think that the found relations between the time perspective and time awareness as well as the age differences are representative for people in industrialized nations. Finally, one methodological issue has to be mentioned: retrospective judgments of duration are supposed to rely on memory retrieval processes pertaining to episodic memories of time spans lived [
23,
24]. However, this relationship has still not been demonstrated directly through measures of episodic memory and by comparing memory retrieval for various life spans between different age groups. This approach would amount to a huge logistical endeavor but would probe directly whether our assumptions are valid, namely that subjective life expands with a greater amount of memories present for a given interval of our life.
Another open question pertains to the fact that the last 10 years, and not the last year, is sensitive to age differences, and that emotion regulation and a balanced time perspective are related to the felt passage of the last 10 years, but not to the last year. Adults indeed often complain how the last year has again passed by so quickly. One possible answer would be that in our study individuals compared the last interval (1 year/10 years) with the preceding same interval, and the felt contrast between the last 10 years and the preceding 10 years is larger than the contrast between the last year and the preceding year. However, these methodological issues have to be addressed in future studies.