Who Signs Up for Singlehood and Romantic Relationship Studies? Examining Volunteer Bias in Online Recruitment

Research involving self-report methods risks volunteer bias, which can undermine validity by attracting particular participant types. What is the risk of such bias when participants choose studies on online recruitment platforms? The current study (Study 1: N = 1,595; M_age = 28.45; Study 2: N = 2,777; M_age = 31.18) examined volunteer bias in online studies, using the context of recruiting individuals for singlehood and romantic relationship research. Participants were recruited via Prolific for a study about "people's lifestyles," or "singlehood [or romantic relationships] and people's lifestyles." We assessed and compared their demographics, individual differences, feelings about singlehood/partnership, and well-being. No consistent differences emerged across recruitment framings, suggesting that advertisement wording did not selectively attract distinct Prolific participants. These data support one aspect of the validity of online singlehood and relationship research, suggesting that low-effort studies conducted on online platforms may suffer less from volunteer bias than other research recruitment strategies.