中文摘要：

对小学3、4年级的285名儿童进行了3年追踪调查，分析了儿童分别与男、女生互选友谊数的变化趋势及其在个体间的差异，探讨了外部攻击和关系攻击分别对两类互选友谊数的影响。结果表明：（1）儿童的男、女生互选友谊数在3年时间内都有显著的增加趋势，并表现出显著的性别差异，儿童与同性互选友谊数显著多于他们与异性的互选友谊数，男生与女生互选友谊数的增加速度比女生与女生互选友谊数增加速度慢，儿童与男生的互选友谊数越多，他／她与女生的互选友谊数就越少，表明了性别疏离现象的存在。（2）在控制了关系攻击的影响后，儿童的外部攻击对他们在各时间点测得的与女生的互选友谊数有显著的消极影响，而对他们与男生的互选友谊数影响不显著；在控制了外部攻击的影响后，儿童的关系攻击对他们在各时间点测得的与女生的互选友谊数有显著的积极影响，而对他们与男生的互选友谊数影响不显著。这说明外部攻击和关系攻击对儿童互选友谊数的影响存在性别差异。

英文摘要：

A great deal of research documents the importance of relationships such as mutual friends for a child＇s development and the importance of negative behaviors such as aggression for a child＇s maladjustment. However, previous research on peer relations, especially in China, has been limited in two crucial ways： （1） most of the studies have employed crosssectional designs, which precludes directly examining developmental changes; and （2） few studies have analyzed for influences between friendships and aggression. The present research investigated developmental trends and individual differences for children＇s mutual friendship and explored the longitudinal effects of aggressive behavior on children＇s mutual friendship s. Data were collected for 285 students from Grade 3 and Grade 4 in June of 2002, 2003 and 2004. M easures included （1） Friendship Nominations, from which we determined each child＇s number of mutual friends with boys and with girls; and （2） peer nominations for overt aggression and relational aggression behaviors, using the Revised Class Play procedure. The present study employed Hierarchical Linear Model to analyze the longitudinal data. In terms of friendships, results indicated that, as expected, the number of mutual friends increased over time and children had more same sex mutual friends than opposite sex mutual friends. This same sex preference increased more for girls than for boys. For girls, having more mutual friends at the first assessment predicted a faster rate of accumulating mutual friends during the three years. After controlling for the effect of relational aggression, overt aggression had a significantly negative effect on the number of children＇s mutual friends at each time of testing for girls but not for boys. After controlling for the effect of overt aggression, relational aggression had a significantly positive effect on children＇s number of mutual friends for girls at each time of testing, but not for boys These findings confirm an increase of mu