Research on interpersonal relationships, especially romantic ones, has increased markedly in the last three decades (see Berscheid & Reis 1998) across a variety of fields, including social psychology, anthropology, ethology, sociology, developmental psychology, and personology (Berscheid 1994). Unfortunately, these diverse perspectives have not coalesced into larger, more integrative theories of how and why relationships function the way they do.Evolutionary principles can integrate the findings on interpersonal relationships, especially concerning mating and parental behavior. In the evolutionary approach one tries to understand human psychological design -the nature, organization, and operation of domain-specific psychological mechanisms -by identifying plausible constraints from selection pressures during evolutionary history (see Buss 1995). Human behavior is highly flexible and environmentally responsive but "[psychological] designs that produce 'plasticity' can be retained by selection only if they have features that guide behavior into the infinitesimally small regions of relatively successful performance

This study examined how adult attachment styles moderate spontaneous behavior between dating couples when 1 member of the dyad is confronted with an anxiety-provoking situation. Eighty-three dating couples were unobtrusively videotaped for 5 min in a waiting room while the woman waited to participate in an "activity" known to provoke anxiety in most people. Independent observers then evaluated each partner's behavior on several dimensions. Results revealed that persons with more secure attachment styles behaved differently than persons with more avoidant styles in terms of physical contact, supportive comments, and efforts to seek and give emotional support. Findings are discussed in the context of theory and research on attachment.Recently, a growing number of researchers have begun to explore how different attachment styles influence what transpires within adult relationships (e.g.,

Individual differences in willingness to engage in uncommitted sexual relations were investigated in 6 studies. In Study 1, a 5-item Sociosexual Orientation Inventory (SOI) was developed. Studies 2, 3, and 4 provided convergent validity evidence for the SOI, revealing that persons who have an unrestricted sociosexual orientation tend to (a) engage in sex at an earlier point in their relationships, (b) engage in sex with more than 1 partner at a time, and (c) be involved in relationships characterized by less investment, commitment, love, and dependency. Study 5 provided discriminant validity for the SOI, revealing that it does not covary appreciably with a good marker of sex drive. Study 6 demonstrated that the SOI correlates negligibly with measures of sexual satisfaction, anxiety, and guilt. The possible stability of, origins of, and motivational bases underlying individual differences in sociosexuality are discussed.

This investigation examined the impact of secure, anxious, and avoidant attachment styles on romantic relationships in a longitudinal study involving 144 dating couples. For both men and women, the secure attachment style was associated with greater relationship interdependence, commitment, trust, and satisfaction than were the anxious or avoidant attachment styles. The anxious and avoidant styles were associated with less frequent positive emotions and more frequent negative emotions in the relationship, whereas the reverse was true of the secure style. Six-month follow-up interviews revealed that, among those individuals who disbanded, avoidant men experienced significantly less post-dissolution emotional distress than did other people.

This research examined lay relationship and partner ideals in romantic relationships from both a social-cognitive and an evolutionary perspective. Studies 1 and 2 revealed that the qualities of an ideal partner were represented by 3 factors (partner warmth-trustworthiness, vitality-attractiveness, and status-resources), whereas the qualities of an ideal relationship were represented by 2 factors (relationship intimacy-loyalty and passion). A confirmatory factor analysis in Study 3 replicated these factor structures but found considerable overlap across the partner and relationship dimensions. Studies 4 and 5 produced convergent and discriminant validity evidence for all 5 factors. Study 6 indicated that the higher the consistency between the ideals and related assessments of the current partner and relationship, the more positively the current relationship was evaluated.