Simply having an older sibling has also been linked to adolescent empathy development. Longitudinal research conducted by Tucker, McHale and Crouter (2001) of 197 families with one or more adolescent found that siblings influence adolescent empathy development in numerous ways. Overall, the authors concluded that adolescents with older siblings tend to exhibit higher levels of empathy when compared to those adolescents without an older sibling. Further, beyond the mere presence of an older sibling, the quality of the relationship between the older and younger sibling, as well as the older sibling's gender, can affect the younger sibling's empathy development. Specifically, Tucker et al. (2001) found that younger sisters had greater empathy when their older siblings were more empathic, that younger sisters of older brothers were more empathic than were younger sisters of older sisters, and that younger sisters reported the highest levels of empathy when older brothers displayed more positive behaviors and when their sibling relationship could be characterized as highly positive. Similarly, even in female adolescent-older sister relationships that were characterized as more negative than positive, the younger sister reported greater levels of empathy than did adolescent females without an older sibling. With respect to younger brothers, the authors found that both having a more empathic older brother and having a positive sibling relationship were linked with development of empathy; in fact, simply having an older sibling was positively linked to greater empathy development for males. Unlike younger sisters, younger brothers tended to focus only on older brothers as role models (Tucker, McHale, & Crouter, 2001).