Instrumentality boosts appreciation: helpers are more appreciated while they are useful.

We propose that in social interactions, appreciation of a helper depends on that helper's instrumentality: The more motivated one is to accomplish a goal, and the more one perceives a helper as able to facilitate that goal, the more appreciation one will feel for that helper. Four experiments supported this instrumentality-boost hypothesis by showing that beneficiaries felt more appreciation of their helpers while they were receiving help toward an ongoing task than after that task was completed or after the helper was deemed no longer instrumental. This finding held for both the positive side of appreciation (gratitude) and the negative side (feelings of indebtedness) and also across a range of relationships (complete strangers, newly acquainted partners, and friends). This pattern of appreciation is counterintuitive for helpers, and so a mismatch arises between the time courses of beneficiaries' experienced appreciation and helpers' expectations of appreciation.