Inclusion Motivation: Measuring the Drive to Be Included in Real Time and How It Is Affected by Loneliness

Humans have a fundamental need to belong and affiliate with others. The term inclusion motivation, coined here, represents the drive of the individual toward an active attempt to be included, at least as equally as others, in social interactions. It is postulated to be triggered by social exclusion and further influenced by personal traits and other stable conditions. To assess inclusion motivation, we developed the active inclusion task (AIT), which is based on the cyberball paradigm. The AIT allows participants for the first time to actively influence their inclusion during conditions of fair play and exclusion, by waving a virtual hand controlled by keyboard presses. In the first step of our study, we examined how different levels of required effort affect the performance of participants (N = 154) by using two versions of the AIT that differ in the magnitude of influence generated by each keypress. Using basic measures of motivation, we found that behavioral inhibition predicted lower numbers of keypresses during exclusion compared with fair play, only when high effort was required. Conversely, higher behavioral activation predicted higher numbers of keypresses across conditions. In the second step of our study, we tested whether loneliness accounts for differences in inclusion motivation. Results show that higher loneliness score predicted higher number of keypresses during exclusion compared with fair play, only when low effort was required.