Understanding and Preventing Violence, Volume 2: Biobehavioral Influences (1994)
Chapter: EFFECTS OF HORMONES ON PERCEPTION
greater than 80 on the Wechsler Adult Intelligence Scale (WAIS)). It was found that subjects with convictions for only violent crimes have a higher ratio of these adrenomedullary hormones than either subjects with a mixed violence and property crime background or those with convictions for sexual offenses. Woodman (1983) suggests that this finding supported the view that increased norepinephrine production (relative to epinephrine) "is found in more aggressive personalities."
"INDIRECT" EFFECTS ON AGGRESSION AND HOSTILITY
It is obvious, when reading the literature on associations between aggression and hormones in lower vertebrates, primates (see Dixson, 1980), and humans, that many of the associations are mediated via changes in the social signals employed between conspecifics (Brain, 1977–1979a). Barnett (1967) defined a "social signal" as "a small amount of energy or matter which induces a large change in the rate of energy release in a system, and it is produced by an animal and acts on another of the same species." Somewhat in contrast, Poole (1985) suggested that a "social signal is behavior which has evolved to convey information to a conspecific with the object of modifying its behavior for the benefit of the signaller." The latter author felt that there were basically two types of social signals, namely, discrete and graded. The alarm call of a ground squirrel (Spermophilus parryi) is a discrete signal. Aggressive vocalizations and threat displays, however, generally consist of a series of graded signals. Indeed, threat has been defined as a signal that potentiates withdrawal of a conspecific (Barnett, 1975), and one would expect the use of different intensities of display for different purposes. A comparative approach to social communication has revealed the great variety of signaling methods used by different species.
The endocrine system can serve as a "go-between" in such social communication. Kelley (1981) has described three ways in which endocrine mediation may be involved in social signaling. These are described separately below.
EFFECTS OF HORMONES ON PERCEPTION
The term "perception" refers to the processing of sensory input by the CNS (Gandelman, 1981). It is important to distinguish between the processing of information that is involved in the perception of an individual relationship in a given situation and
