Touch: a comprehensive review of its physiological, emotional, and relational effects

Touch is an important part of human communication and social interaction. It can convey many messages, including comfort, affection, reassurance, support, love, pleasure, attraction, appreciation, gratitude, desire, and more. Touch is also essential for physical health and well-being; it regulates heart rate, blood pressure, immunity, stress response, weight management, and much more. Touch research has been conducted since the late 1800s when Charles Darwin investigated how different types of touch affected animals' behavior. However, the psychophysiology of touch, or its effects on the body and mind, remains poorly understood. This review summarizes recent findings from studies that examine how touch influences emotions, mood, cognition, memory, attention, empathy, creativity, and learning. The effects of touch depend on factors like age, gender, culture, context, personality, experience, expectations, relationship quality, and individual differences such as trauma history, anxiety, depression, and addiction. For example, tactile stimulation may boost oxytocin levels to promote attachment and trust while inhibiting fear and pain perception. Other studies show that erotic touch increases brain activity in regions associated with reward processing and sexual arousal (e.g., ventral striatum) and decreases activity in regions involved in self-control (e.g., dorsolateral prefrontal cortex). Additionally, touch affects hormones like testosterone and dopamine, which regulate libido and other aspects of sexuality. Finally, touch can activate the autonomic nervous system, leading to increased respiration, heart rate, blood flow, sweating, and pupil dilation. Overall, touch is a complex and multidimensional phenomenon that scientists are just beginning to understand. It holds promise for enhancing health, relationships, and wellbeing, but it also carries risks related to physical and mental safety, social rejection, intimacy issues, communication problems, and even pathological sexual behaviors.