Abstract:

The economy of action argues that individuals’ perceptions of the physical environment are related to the resources they possess. Anxiety is an emotion characterized by an unpleasant state of inner turmoil, often associated with threat or risk, that can be viewed as a manifestation of inadequate coping resources. Therefore, anxiety may affect individuals’ perceptions of the physical environment around them. Previous studies have shown that exercise influence perceptual judgments mostly based on vision-based perceptual indicators, and rarely involved stress anxiety and trait anxiety that are more common in the field of life. However, this study employed weight-based perception indicators rather than vision-based indicators to investigate the effects of two kinds of state anxiety in daily life with different mechanisms and the more stable trait anxiety on the perception of object weight, and proposed the following research hypothesis: individuals perceived objects as heavier in state or trait anxiety.

In the present work, we conducted three studies to systematically investigate the effects of three types of anxiety with different attributes on the perception of weight: body posture-induced anxiety (Experiment 1), external task-induced anxiety (Experiment 2), and trait anxiety, which is stable at the personality level (Experiment 3). Participants in both Experiment 1 and Experiment 2 were asked to report their anxiety before and after the experimental task was manipulated and to judge the weight of the backpack they carried. In Experiment 1, 64 participants were randomly assigned to the anxious body posture group (n = 32) and the relaxed body posture group (n = 32) by being asked to do different body postures. In Experiment 2, 65 participants were randomly assigned to either the mental arithmetic task group (n =33) or the odd-even task group (n = 32). In Experiment 3, based on the scores of the Trait Anxiety Inventory (T-AI) Scale, high and low scorers were selected to constitute a high-level trait anxiety group (n = 64) and a low-level trait anxiety group (n = 64), and were asked to perceive the post-test weight of the three backpacks.

The results of three experiments showed that the influence of anxiety on weight perception. In Experiment 1, we found that the anxious body posture induced anxiety. A 2 (group: anxious body posture group vs. relaxed body posture group) × 2 (order: before vs. after) mixed ANOVA was adopted and results showed that main effect of group was not significant, F(1, 62) = 1.84, p= 0.180, the main effect of order was significant, F(1, 62) = 21.27, p < 0.001, η²_p = 0.26, 90% CI = [0.11, 0.39]. There’s a significant interaction between group and order, F(1, 62) = 10.89, p= 0.002, η²_p = 0.15, 90% CI = [0.04, 0.28], participants in the anxious body posture group perceived the weight of the object as heavier than those in the relaxed body posture group (see Figure 1). The results of Experiment 2 revealed that the stressful mental arithmetic task induced anxiety. A 2 (group: mental arithmetic task group vs. odd-even judgment task group) × 2 (order: before vs. after) mixed ANOVA revealed that main effect of group was not significant, F(1, 63) = 2.49, p= 0.119, the main effect of order was significant, F(1, 63) = 21.17, p< 0.001, η²_p = 0.25, 90% CI = [0.11, 0.38]. There’s a significant interaction between group and order, F(1, 63) = 7.36, p= 0.009, η²_p = 0.11, 90% CI = [0.02, 0.23]. As illustrated in Figure 2, participants in the mental arithmetic task group perceived the weight of the object as heavier than those in the odd-even judgment task group. The results of Experiment 3 indicated that participants in the high-level trait anxiety group (M = 6.39, SD = 3.88) perceived the weight of the object as heavier than those in the low-level trait anxiety group (M = 4.63, SD = 1.93), t(126) = -3.25, p = 0.002, Cohen's d= 0.58, 95% CI = [0.69, 2.84] (see Figure 3).

The results of the three experiments suggest that either the state anxiety induced by physical changes or cognitive evaluations, or the more stable trait anxiety at the personality level, affects individuals’ perceptions of physical properties of objects, leading them to perceive objects as heavier. This study extends the indicator of perception from the visual to the weight domain at the theoretical level, validates and extends the economy of action theory again; the revealed features of weight perception of anxious individuals provide a new physical perspective for anxiety intervention, and such findings can be applied to the design of human-computer interfaces in the future, which is of great practical significance.

Key words: anxiety, weight, perception, judgement