Empathy: The genetics-environment-endocrine-brain mechanism

Abstract

As a vital ability for everyday communication and survival in a socical environment, empathy, including affective empathy and cognitive empathy, plays a crucial role in helping individuals feel, understand and share the emotional state of others. Affective empathy was defined as sharing experiences of emotional states perceived in others, including emotional contagion and affective perspective taking; cognitive empathy involves the ability to engage in the cognitive processes of adopting another′s psychological point of view as well as understanding other′s affective and cognitive mental states, similar to Theory of Mind (ToM). Given that empathy provides the foundation of motivation and emotion in individual moral development, it can be used in clinical practice to optimize the medical treatment by promoting patient–physician communication, reducing patients′ anxiety and distress. Thus, it is full of social significance and clinical meaning to comprehensively and deeply explore the biological basis of empathy. To get a better understanding of empathy, this paper will review relevant research on empathy and list the possible influential factors that may affect one′s empathy. First, based on the evidence from neuroimaging study on both healthy individuals and patients with brain lesions, we summarized the neural basis of affective empathy and cognitive empathy. These findings indicate that affective empathy involves specific brain areas, such as insula, anterior cingulate cortex (ACC), and inferior frontal gyrus (IFG). In contrast, ventromedial prefrontal cortex (vmPFC) is specific to cognitive empathy. Second, we expatiated the factors related to endocrine system that may influence individuals′ empathy and their related behaviors. Whereas oxytocin facilitates the response of empathy, testerone weakens it. In addition, fetal testosterone would influence the development of individual empathy. Third, the development of empathy can also be affected by the genetic polymorphism of oxytocin receptor (OXTR), zinc finger protein 804A (ZNF804A), serotonin transporter (5-HTTLPR), and D4 dopamine receptor (DRD4). With the development of a child, the influences of environmental factors, such as characteristics of family members, parenting styles, and schooling, on empathy cannot be ignored. Taken all these possible factors into account, a theoretical framework for understanding empathy is proposed, which comprehensively reveals the biological basis of empathy and how it can be affected by genetics, environment, endocrine, and brain. Furthermore, we discussed the shortcomings of previous studies on empathy, mainly due to the small sample size and/or the isolation of influential factors from the whole theoretical framework. Finally, we emphasized that further investigations on empathy should focus on longitudinal studies with large sample size, and make efforts to reveal the interactions of the influential factors (e.g. genetics, environment, endocrine and brain). More importantly, experimental findings of empathy research should be well explained and translated to the social and clinical applications, as the improvement of empathy can be used in promoting social harmony and enhancing clinical treatment.