Zimmer-Gembeck and colleagues (2001) studied dating practices in a sample of 16-year-olds in Minneapolis. As part of their study they examined the relation of dating involvement, experience, and quality with various aspects of self-concept and self-worth (that is, how positively the 16-year-olds rated themselves on such things as scholastic competence, social acceptance, and so on). However, the researchers were concerned that the correlations among these variables would be inappropriately influenced by differences in the appearance of physical maturity (how old the person looks). Thus, their results, shown in Table 15-9, provide correlations "controlling for appearance of physical maturity".
Explain this method and the pattern of a few example results to a person who is familiar with correlation and multiple regression but is unfamiliar with partial correlation.
Table 15-9
Partial Correlations (Controlling for Appearance of Physical Maturity) of Dating and Self-Concept at Age 16

Level of Dating Quality of Romantic Relationship with Dating -0.10 0.04 0.06 -0.12 0.10 Self-Concept/Self-Worth 0.08 0.24 0.24 0.12 0.35 -0.03 Social acceptance Physical appearance Job competence Romantic appeal Behavioral conduct Close friendship Global self-worth 0.29* 0.11 0.07 0.36 -0.04 0.09 0.18 -0.33 0.00 0.09 0.05