Describe the factors that psychologists have studied as causes of human aggression.?

What will be an ideal response?

ANSWER:
?Research on the relationship between aggression and
testosterone
has yielded a somewhat confusing picture. Sometimes higher levels of testosterone are associated with higher levels of aggression in animals (Müller, Moe, & Groothuis, 2013; Wagner, Beuving, & Hutchinson, 1980), but sometimes they are not (Eaton & Resko, 1974). Like- wise, human studies sometimes show a correlation between high testosterone levels and aggression (Dabbs & Morris, 1990; Sánchez- Martín et al., 2011; Van Goozen, Frijda, & de Poll, 1994), but sometimes they fail to find a clear relationship (Coccaro et al., 2007). Even if the correlation between testosterone and aggressive behavior were more consistent in the literature, it would still be difficult to determine the actual cause(s) of aggressive behavior. Recall that correlation does not imply causation.
?
Research has suggested that another chemical, serotonin (see Chapter 2), may also play a role in regulation of aggressive behavior (for a review, see Duke et al., 2013; Libersat & Pflueger, 2004). Researchers measured levels of the neurotransmitter serotonin in the bloodstream of three groups of people: survivors of suicide attempts, people institutionalized since childhood for aggressive behavior, and a normal control group (Marazzitti et al., 1993). They found that the suicide survivors and the aggressive patients had lower levels of serotonin than those in the normal control group.
?
Another connection between biology and aggression comes from research into the backgrounds of incarcerated criminals. During the 1980s and 1990s, psychiatrist Dorothy Otnow Lewis interviewed more than 100 murderers in an attempt to discover whether they had experienced abuse as children (Lewis, 1992). During these interviews, Lewis discovered that an overwhelming majority of these murderers had suffered extreme abuse during childhood. In particular, many had suffered severe head injuries as a result of the abuse, which led Lewis and her colleagues to hypothesize that the murderers’ aggressive tendencies may have resulted from brain damage (Lewis et al., 2004). More recent research seems to reinforce Lewis’s notions.
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One model of aggression, the cognitive neoassociation theory, proposes that cues present during an aggressive event can become associated in memory with the thoughts and emotions experienced during that event (Anderson & Bushman, 2002; Berkowitz, 1990). For example, if you see many instances (real or televised) in which people use guns to shoot and hurt those who have humiliated them, you may begin to associate concepts from these events in your memory. You may begin to associate guns with anger, hurt, fear, and humiliation; or you may begin to associate conflict with shooting. Because these concepts become tightly linked in memory, activation of one of them can prime other related concepts and cause them to become active.
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One key factor in aggression appears to be frustration. According to the frustration-aggression hypothesis (Dollard et al., 1939), when we become frustrated, we activate a motive to harm other people or objects. These motives are likely to be directed at those people or objects that we perceive to be the source of our frustration.