Abstract:

Shyness refers to individuals’ inhibition in a social situation; it can be an obstacle to participation in social interactions. In recent years, there has been an increase in cognitive neuroscience research on shyness. Within the frameworks of the metacognition model of shyness, the social fitness model of shyness, the lateralized brain-body emotion model of shyness, and the differential susceptibility to environmental influences model of shyness, researchers have explored the brain function differences, related brain networks, and cognitive processes underlying shyness. However, current cognitive neuroscience research on shyness is still in its infancy. For example: (1) researchers have mainly defined shyness from the perspective of personality; (2) the theoretical models of shyness are far from perfect; (3) the results of relevant empirical research have been unsystematic and inconsistent.
Based on the above, this study proposes a psychological development model of shyness, which includes the following four perspectives. (1) Timeline of human evolution: the interaction of genetic factors (susceptibility genes), the internal environment (brain), and the external environment (such as school, family, and culture) affects the development of shyness. In the process of human evolution, human beings and their offspring showed different reactivity to the external environment, resulting in the survival of the fittest. The result of this process is that some individuals carry shyness susceptibility genes, which will not only determine their internal environment (brain) but also be affected by their internal environment (brain) and shape their metacognition and cognitive processes under the influences of school, family, culture, and other aspects of the external environment. The brain environment responsible for shyness is an expression of the interaction between the cognitive control system (centered in the prefrontal lobe) and the emotional system (centered in the amygdala-hypothalamus). Specifically, the cognitive bias/emotional arousal of shy individuals is the result of an imbalance in the regulation of the limbic system (centered in the amygdala-hypothalamus) by the prefrontal cortex. In other words, when facing an external stimulus, the amygdala of highly shy individuals is highly activated, which results in a highly emotional interpretation of low-level external stimuli, which is then projected to a wide range of brain regions including the hypothalamus. The hypothalamus then activates emotional expression by regulating the autonomic nervous system. In this process, the prefrontal cortex plays a top-down regulatory role, in which the strong activation of the right prefrontal lobe and the weak activation of the left prefrontal lobe of highly shy individuals leads to the disinhibition of the activated amygdala, hypothalamus, and other brain regions. Thus, the individual’s ability to regulate their emotions becomes weak and they cannot behave in an adaptive manner. The aspects of the internal environment that influence shyness include the differentiation of brain structure, the lateralization of brain function, and the uniqueness of the brain network. Moreover, in specific brain cognitive processing tasks, individuals with different levels of shyness have significant differences in the activity of different frequency bands and different cognitive components. (2) Timeline of individual development: the critical period of individual development affects the development of shyness. Specifically, the key development period of shyness is largely affected by the development of self-consciousness. With the maturity of self-consciousness, the externalized performance of individuals with different levels of shyness can be clearly distinguished. (3) Social situations: in specific social situations, the metacognition of shy individuals guides their cognitive processes, making them show differences in their physical, emotional, and behavioral performance. At the same time, different kinds of social situations will awaken individuals’ shyness to different degrees.
Future research can be carried out from the following perspectives based on the psychological development model: (1) in terms of personality, clarify whether shyness describes a small number of extreme individuals or is instead a dimension that can sort the whole population; (2) explore the internal process of the emotional experience of shyness; (3) develop experimental research paradigms of shyness; (4) with the help of new brain technology, deeply explore the brain mechanism of shyness; (5) verify, expand, and improve the theoretical model related to shyness in the field of cognitive neuroscience.

Key words: shyness, cognitive and neural mechanisms, psychological development model of shyness