The sense of touch allows us to infer objects’ physical properties, while the same input also produces affective sensations. These affective sensations are important for interpersonal relationships and personal well-being, which raises the possibility that tactile preferences are adapted to the characteristics of the skin. Previous studies examined how physical properties such as surface roughness and temperature influence affective sensations; however, little is known about the effect of compliance (physical correlate of softness) on pleasantness. Thus, we investigated the psychophysical link between softness and pleasantness. Pieces of human skin-like rubber with different compliances were pressed against participants’ fingers. Two groups of participants numerically estimated the perceived magnitude of either pleasantness or softness. The perceived magnitude of pleasantness and softness both increased monotonically as a function of increasing object compliance, levelling off at around the end of the stimulus range. However, inter-subject variability was greater for pleasantness than for perceived softness, whereas the slope of the linear function fit to the magnitude estimates was steeper for softness than for pleasantness. These results indicate that object compliance is a critical physical determinant for pleasantness, whereas the effect of compliance on pleasantness was more variable among individuals than the effect on softness was.

触觉使我们能够推断物体的物理特性，同时同样的输入也会产生情感感觉。这些情感感觉对人际关系和个人幸福感很重要，这增加了触觉偏好适应皮肤特征的可能性。以前的研究检查了表面粗糙度和温度等物理特性如何影响情感感觉；然而，关于顺从性（柔软度的物理相关性）对愉悦感的影响知之甚少。因此，我们调查了柔软度和愉悦度之间的心理物理联系. 将具有不同顺应性的人类皮肤状橡胶片压在参与者的手指上。两组参与者以数字方式估计了感知到的愉悦或柔软程度。感知的愉悦度和柔软度都随着物体顺应性的增加而单调增加，在刺激范围结束时趋于平稳。然而，舒适度的受试者间变异性大于感知柔软度，而拟合幅度估计的线性函数的斜率对于柔软度比舒适度更陡峭。这些结果表明，物体顺从性是愉悦感的关键物理决定因素，而顺从性对愉悦感的影响在个体之间比对柔软度的影响更大。