Unfortunately, these data remain correlations, and the exact role of hormones in facilitating paternal behavior or causing couvade symptoms in expectant fathers remains unknown. It is certainly tempting to look to hormones for the biological root of couvade symptoms, but caution is needed. Other events also happen around a pregnancy, especially the birth of a first child, and could independently affect hormone concentrations. Changes in sexual activity, shifts in the social priorities of the couple, time off work, or the arrival of a mother-in-law for a potentially stressful extended visit are obvious candidates. Of course, even if the stimuli causing the hormonal changes are not the result of an approaching birth the hormone changes might produce couvade symptoms and/or facilitate a father's social bond with his child. Either way, this kind of research has quietly expanded the horizons for research on hormones in men--testosterone alone is clearly no longer the sum of the man.