Scaredy-rats die young
High stress life may take toll on longevity.
9 December 2003
HELEN PEARSON

As many as 15% of children may suffer from severe shyness
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A new study raises the prospect that shy people might die younger than extroverts.

As many as 15% of children are thought to suffer from neophobia — a fear of novel but non-threatening situations such as meeting a stranger or entering a new room. They also have higher levels of stress hormones called glucocorticoids.

Now researchers have found that neophobic rats die an average of three months younger than their outgoing brothers — equivalent to ten years shaved off a human life1. The scaredy-rats were chosen because they were reluctant to explore new surroundings.

Over a lifetime, heightened levels of stress hormones might take their toll, suggest Sonia Cavigelli and Martha McClintock of the University of Chicago, who carried out the study. As in frazzled workers who succumb to colds, the immune system might be particularly vulnerable to stress. “It’s having some sort of wear and tear,” says Cavigelli.

Whether timid people also meet a premature fate is unknown. “I don’t want to take a gamble on that just yet,” Cavigelli says. Being neophobic or shy might also have advantages, she points out — such as in helping animals to avoid life-threatening situations.

References
Cavigelli, S. A. & McClintock, M. Fear of novelty in infant rats predicts adult corticosterone dynamics and an early death. Proceedings of the Royal Academy of Sciences, published online, doi:10.1073/pnas.2535721100 (2003).|Article|

© Nature News Service / Macmillan Magazines Ltd 2003