Holman and Jarvis's results were similar, with participants who endorsed the validating type having the highest levels of martial satisfaction and stability. As in the present study, the researchers found that conflict-avoiding and volatile couples had less positive outcomes than validating couples, but were still more likely to have positive than negative outcomes and were more closely related on almost all measures to the validating couples than to the hostile couples. Intriguingly, couples with older babies were more likely to have higher scores on the hostile couple conflict type scale, whereas couples with younger babies were more likely to have higher scores on the validating couple conflict type scale. Because this study was cross-sectional rather than longitudinal (and the sample was volunteer rather than randomly-selected), it cannot be determined whether couples may deteriorate toward an unregulated hostile couple conflict type during their first year after transitioning to parenthood or whether these variations simply reflect differences in the make-up of the sample. However, it may be that partners are more likely to take time to express and validate feelings and work toward conflict resolution when their babies are younger because their roles are not yet as firmly established and the new parents may rely more on each other for support. As babies grow older and become more demanding of attention (with increasing mobility, need to play, etc.), it may be harder for couples to take time to resolve conflicts. Additionally, if parents' roles become more differentiated over their babies' first year, they may have more difficulty understanding and validating each others' perspectives. Such couples may become more vulnerable to slipping out of a regulated conflict style and into the unregulated hostile couple conflict style.