Fear of new things may shorten life

Being afraid of new experiences may lead to a shorter life. According to recent research, fearful rats produced more stress-related hormones when exposed to new experiences and they tended to live shorter lives than less adventurous rats. Whether the same is true in people is uncertain, but studies have shown that shy children experience a surge in stress hormones when confronted with something new. Young rats identified as fearful produce more stress hormones across the life span, according to researchers at the University of Chicago's Institute for Mind and Biology, USA. The increased production of stress hormones may accelerate ageing. How personality and other behavioural traits affect the physiology and what kind of impacts these traits could have on health over the life span was studied. In rats that were more fearful than others, the trait showed up early in life and persisted throughout life. When placed in a new environment, fearful rats were hesitant and did not explore their new surroundings very much. In contrast, rats that were not fearful moved throughout their new surroundings and inspected objects around them. Fearfulness was apparent in rats early in life, even before they were weaned, and it persisted into adulthood, according to the report. Compared to other rats, fearful rats experienced a surge in hormones called glucocorticoids after being exposed to something new. Fearful rats lived an average of 20 percent shorter lives than more adventurous rats. The association between increased secretion of stress hormones and a shorter life suggests that the hormones may gradually cause damage that accelerates ageing. But it is important to note, that fearfulness or shyness may not always be a negative trait. Future research should focus on how social experiences early in life affect the development of fearfulness.