We propose that in social interactions, appreciation depends on the helper’s instrumentality: The more motivated one is to accomplish a goal and the more one perceives a potential helper as ableto facilitate that goal, the more appreciation one will feel for that helper. Three experimentssupport this instrumentality-boost hypothesis by showing that beneficiaries feel moreappreciation for their helpers while they are receiving help toward an ongoing task than after thattask has been completed or after the helper has been deemed no longer instrumental. This holdsfor the positive side of appreciation (gratitude) and the negative side (indebtedness), and across arange of relationships (complete strangers, new partners, and friends). This pattern ofappreciation is counterintuitive for helpers, resulting in a mismatch between the time courses ofexperienced and expected appreciation.