Table 1.
A Summary of Evidence for the Progression Bias.
| Relationship initiation | ||
| Behavioral evidence | Citations | |
| People pursue potential partners who do not meet their stated dating standards | Eastwick et al. (2011); Slotter and Gardner (2012); Joel et al. (2014) | |
| People “yes” a relatively large portion of options in speed-dating contexts, including those who do not conform to stated preferences | Kurzban and Weeden (2007); Joel, Eastwick, & Finkel (2017) | |
| People evaluate brand-new potential romantic partners in a positively biased way | Berscheid et al. (1976) | |
| Relationships that begin as casual sexual encounters frequently transition into committed relationships | Machia et al. (2020); Owen and Fincham (2012); Timmermans and Courtois (2018) | |
| When presented with many dating options, people take a satisficing approach of rejecting the worst options rather than selecting the best options | Jonason et al. (2015); Long and Campbell (2015) | |
| Potential mechanisms | ||
| Motivational | Fear of being single leads to less selective mate decisions | Spielmann, MacDonald, et al. (2013) |
| Motivational | Missing a romantic opportunity is perceived to be more regrettable than being rejected | Joel et al. (2019) |
| Cognitive | Humans are poorly equipped to exhaustively evaluate a large number of mating options | Lenton et al. (2008; Lenton & Francesconi, 2010); Wu and Chiou (2009) |
| Evolutionary | In simulation studies, agents with less selective mate strategies are more successful and become more populous | Neth et al. (2011); Todd (1997) |
| Social | Single individuals face stigma for not being in relationships | Conley and Collins (2002); Hertel et al. (2007); Greitemeyer (2009); Morris et al. (2007) |
| Relationship advancement | ||
| Behavioral evidence | Citations | |
| In samples of young, single individuals, a nontrivial percentage (~30%) tend to fall in love within a few months | Aron et al. (1995); Gerlach et al. (2019) | |
| Even relationships labeled as casual or short-term tend to follow investment trajectories that are indistinguishable from long-term relationships | Eastwick et al. (2018) | |
| People come to view new romantic partners as attachment figures within the first few months of dating | Heffernan et al. (2012); Fagundes and Schindler (2012) | |
| People in brand-new relationships adjust their dating standards and goals to match their new dating partners | Gerlach et al. (2019); Fletcher et al. (2000); Gere and Impett (2018) | |
| Potential mechanisms | ||
| Motivational | Sexual desire motivates investment behaviors | Birnbaum et al. (2017); Gillath et al. (2008) |
| Motivational | Investment from one partner motivates commitment from the other, even when the relationship is low quality | Joel et al. (2013) |
| Biological | Romantic love is associated with reward systems in humans (e.g., heightened activation of the ventral tegmental area [VTA]) | Acevedo and Aron (2014); Burkett and Young (2012); Aron et al. (2005); Bartels and Zeki (2000, 2004); Xu et al. (2011); Acevedo et al. (2012) |
| Biological | Pair-bonding is also linked to reward systems in other animals such as prairie voles | Burkett et al. (2011); Johnson and Young (2015); Aragona et al. (2006) |
| Cognitive | The decision to move in together is often made with little conscious deliberation | Lindsay (2000); Manning and Smock (2005); Sassler (2004) |
| Relationship maintenance | ||
| Behavioral evidence | ||
| People show a preference for existing partners over more attractive partners even in hypothetical contexts | Gunaydin et al. (2018) | |
| Many struggle to leave even unhealthy or abusive relationships | Arriaga (2002); Arriaga et al. (2013); Rusbult and Martz (1995) | |
| Dissolved partnerships frequently reconcile | Dailey, Rossetto, et al. (2009); Dailey, Pfiester, et al. (2009) | |
| Potential mechanisms | ||
| Motivational | Relationship investments create barriers to dissolution | Rusbult et al. (1998); Stanley et al. (2006) |
| Motivational | Concern for the partner’s feelings creates barriers to dissolution | Perilloux and Buss (2008); Joel, Impett, et al. (2018) |
| Motivational | Fear of being single creates barriers to dissolution | Spielmann, MacDonald, et al. (2013) |
| Motivational | Break recovery is as difficult for rejectors as it is for rejectees | Sbarra (2006) |
| Biological | Endogenous opioids play a role in relationship maintenance | Inagaki et al. (2016; Inagaki, 2018); Panksepp et al. (1980); Panksepp (1998); Tchalova and MacDonald (2020) |
| Biological | Even temporary separation from a romantic partner is associated with physiological dysregulation | Diamond et al. (2008) |
| Cognitive | Breakup decisions tend to be deliberative and effortful | Battaglia et al. (1998); VanderDrift et al. (2009); Joel, Eastwick, & Finkel (2017) |