AA << have uncovered an unexpected benefit of (..) personalities [like shyness and aggressiveness]: to protect societies from extreme temperature changes. >>
<< This work focused on the tangle web spider, known to scientists as Anelosimus studiosus, which lives in North Carolina and across North and South America. >>
<< In this species, individual spiders have either one of two personalities: docile or highly aggressive. Together, they not only share the same living space but also share in the duties of brood care and capturing of prey. >>
AA << looked at the effect of temperature – 75 to 93 degrees Fahrenheit – on the spiders' ability to survive and reproduce as an individual and within a colony. They found that aggressive spiders were less likely to survive and reproduce at higher temperatures. But the opposite was true for docile spiders: as the temperature heated up, the better they reproduced and survived. The researchers saw the same pattern when the colonies were made up of all aggressive individuals or all docile ones. But when a colony had different personalities – a mix of aggressive and docile spiders – the aggressive spiders didn't die in hot temperatures and docile ones didn't die in cooler ones. >>
Thania Benios. Temperature helps drive the emergence of different personalities in spiders. July 21, 2016.
http://uncnews.unc.edu/2016/07/21/54073/
Celine T. Goulet, Spencer J. Ingley, et al. Thermal effects on survival and reproductive performance vary according to personality type. Behavioral Ecology, 2016; arw084 DOI: 10.1093/beheco/arw084
http://dx.doi.org/10.1093/beheco/arw084