As of 14 March 2019 the participant referral scheme has been retired. Participants who have signed up via referral link and have not yet cashed out have until 12 May 2019 to do so. If these participants cash out after 12 May 2019 the referrer will not receive their referral fee. 

At Prolific, building a high quality pool of participants to take part in world-leading research is one of our biggest priorities. We are keen to grow this pool in as balanced a way as possible, to discourage population biases and maximise diversity.

This is a decision we have carefully considered as a team. Analyses performed by our research team indicate that participant referrals can cause problems by reinforcing certain demographics in our participant pool – a tendency we would like to curb in order to improve the diversity of our pool.

This change has some upsides for both researchers and participants: It will allow us to distribute studies across our pool more evenly. This should mean that fewer participants will find it hard to get any studies.

Please note that the researcher referral scheme is still active.