Willard F. Harley

His Needs, Her Needs is built on a list of ten emotional needs and the claim that men and women typically rank them differently, with affection and conversation at the top for one and sexual fulfilment and recreational companionship for the other.

Harley worked as a marriage counsellor for decades and the material is aimed squarely at preventing affairs, which he treats as the predictable consequence of unmet needs, not simply a moral failure.

The gendered ranking is the weakest part and is not well supported. The underlying instruction, to find out what your partner actually needs and provide it deliberately, survives without it.