hormonal mechanisms

• Testosterone levels change across the course of the day and specifically during social interaction e.g competitions.
• Mehta and Jones (2006) devised a competitive game where all pps lost. They were given a choice after the second sample was taken, they could either challenge the victorious opponent to a rematch (aggressive) or complete an unrelated task (non-aggressive). Of those whose testosterone levels rose after their loss, 73% rechallenged, but of those who’s testosterone dropped, only 22% rechallenged.
• Carre and Mehta’s (2011) dual hormone hypothesis claims that high levels of testosterone lead to aggressive behaviour only when levels of cortisol are low because when it’s high, testosterone’s influence on aggression is blocked.
• Cortisol is a hormone that plays a central role in the stress response.
• Nanne van der Poll et al (1988) showed female rats who’d been injected with testosterone became more physically and sexually aggressive, proving there is a link between testosterone and aggression.