Our analyses and overview of previous research suggest that the bully-victim group is small, and that the large variations across studies are mainly due to differences in choice of cutoff point. Bully-victims should generally be seen and treated statistically as a distinct subgroup. The relatively larger proportion of bully-victims in lower grades should be explored further.

The results provide strong support for the 'enhancement hypothesis'. The negative effects in boys seemed to stem from both the practice of power sports itself and from repeated contact with 'macho' attitudes, norms, and ideals. The negative effects of participation in power sports represent a societal problem of considerable dimensions which has been largely neglected up to now.

Empathy or empathic responsiveness concerns the reactions of one individual to the experience of another: "a vicarious emotional response to the perceived emotional experience of others" (Mehrabian & Epstein, 1972, p. 525). Bamett (1987 ) offers a similar, somewhat more elaborate definition: "empathy denotes the vicarious experiencing of an emotion that is congruent with, but not necessarily identical to, the emotion of another individual" (p. 146). In this chapter we review a study that examined sex differences and age trends in empathic responsiveness.It is common to differentiate between two emotional or affective facets of empathy: empathic concern and personallempathic distress (Davis, 1983;Lennon & Eisenberg, 1987). Lennon and Eisenberg's (1987) concept of personal distress occurs when an individual's vicarious experience of emotion is Those parts of this chapter that deal with age trends and sex differences in empathic responsiveness are to a considerable degree based on Olweus and Endresen (1998). Adapted with permission. The research program reported on in this chapter was supported by grants from the Ministry of Families and Children's Affairs, the Johann Jacobs Foundation and, in earlier phases, from the Ministry of Education to Dan Olweus, which :are gratefully acknowledged.

The main goals of the study were to examine age trends and sex differences in empathic responsiveness, particularly empathic concern for others in distress. It was based on four cohorts of Norwegian students aged 13 to 16, comprising a total of 1193 boys and 1093 girls. The key measurement instrument was a partly new questionnaire on empathic responsiveness in which sets of items were differentiated according to sex-ofstimulus object. The empirical analyses showed convincingly that differentiation of the items with regard to sex-of-stimulus object was of critical importance for the discovery of the age trends that were present for boys and girls. Girls showed the most straightforward development, with an increase over age in empathic concern towards both girl and boy stimuli. The boys evinced a similar developmental pattern with regard to girls as stimuli but showed a clearly deviating, decreasing trend in empathic concern for other boys in distress. Failure to consider sex-of-stimulus object is probably the main explanation for the inconsistent results previously reported for developmental trends in empathic responsiveness from age 11. In addition, and in agreement with previous research, we found very marked sex differences, with a strong predominance of lowempathic boys and a similarly marked predominance of high-empathic girls. Finally, the empirical analyses indicated the meaningfulness of partly separating out another facet of empathic responsiveness, i.e. empathic distress in which the emotional reaction is assumed to be more oriented toward the self than to the other, while the opposite is true of empathic concern. The results are discussed within an evolutionary perspective.

Factorial analyses of subjectively felt health complaints in a population of 400 males and 74 females revealed nine orthogonal (independent) factors. One factor (Factor 4) involved pain in the neck, pain in the back, pain in arms and shoulders, and migraine. This type of complaint did not relate to anxiety and depression. The prevalence of muscle pains varied between the sexes, and the types of occupations. Shiftwork was also important. 54% of the women and 40% of the men in the total population had some forms of muscle pain, but only 8% of the women and 3% of the men felt this to be a really serious problem. Psychological factors explained only moderate amounts of variance of muscle pain when the population was taken as a whole. However, within each type of occupation, psychological factors explained a considerable amount of the variance.