People are more willing to help strangers they perceive as agreeable or conscientious

People may be more willing to help strangers who seem agreeable and conscientious, partly because these traits make the person more likeable, according to research published in Evolutionary Psychological Science.

Cooperation requires people to decide whether another person is worth helping even when they know very little about them. Because we cannot directly observe how a stranger will behave in the future, these decisions often depend on limited social cues. Previous research suggests that personality traits can provide this kind of information by signalling relatively stable patterns of behavior.

For example, agreeableness, which is associated with trust, empathy, and concern for others, has consistently been linked with cooperation and helping, making it a potentially useful cue when evaluating a possible social partner. Conscientiousness may offer a different kind of information. Rather than primarily signalling warmth or cooperative motivation, it can suggest reliability, self-control, and consistency, qualities that may make someone seem like a dependable partner.

Ryo Oda examined whether people use these personality characteristics when deciding whom to help, and whether a person’s own personality changes how strongly they respond to the same traits in others. The study focused especially on agreeableness and conscientiousness, while also examining openness and extraversion, and tested whether patterns that look like a preference for similar people might instead reflect greater responsiveness to socially desirable traits.

Oda first created 40 short personality profiles in Japanese representing different levels of openness, conscientiousness, extraversion, and agreeableness. For each trait, five profiles were designed to represent relatively high levels and five relatively low levels. A separate preliminary sample of 61 Japanese adults rated these profiles to confirm that the intended personality differences were successfully conveyed.

Personality ratings were based on selected items from the short form of the Japanese Big Five Scale, and the high- and low-trait profiles were successfully distinguished for all four personality dimensions.

The main study included 120 Japanese adults (60 women and 60 men). Participants were evenly distributed across the 20-29, 30-39, 40-49, and 50-59 age groups. Each participant viewed all 40 personality profiles in randomized order.

For every target, participants rated how willing they would be to help in four situations: financial trouble, lying on a railway crossing as a train approached, struggling with heavy luggage, and wanting someone to listen to them. These ratings were averaged into a helping score. Participants also rated how much they liked each target using ratings of liking and friendliness.

All helping and liking items were rated on 9-point scales ranging from 1, “not at all,” to 9, “extremely.” Participants then completed the short form of the Japanese Big Five Scale to assess their own personality traits.

Agreeableness and conscientiousness stood out as the traits most relevant to helping decisions. Targets described as more conscientious received higher willingness-to-help ratings, and this relationship was particularly strong among participants who were themselves more conscientious.

Similarly, more agreeable targets received higher helping ratings, while more agreeable participants were also generally more willing to help. Agreeable participants were especially responsive to agreeableness in the people they evaluated. By contrast, openness and extraversion did not significantly predict helping intentions.

The same broad pattern appeared when participants rated how much they liked each target. More conscientious and more agreeable targets were evaluated more positively, particularly by participants who were themselves higher on the corresponding trait. However, additional analyses suggested that this was not simply a matter of people preferring others whose personalities matched their own. Instead, people higher in agreeableness or conscientiousness appeared especially responsive to those desirable traits in others.

Exploratory mediation analyses further showed that liking statistically accounted for the interactions between participant and target personality in predicting helping: once liking was taken into account, the previously significant interactions for agreeableness and conscientiousness were no longer significant. This suggests that these personality cues may influence helping largely by shaping how positively people evaluate a potential social partner.

Of note is that the study measured hypothetical willingness to help rather than actual helping or partner-choice behavior, so it cannot establish whether the same patterns occur when people must incur real costs. The sample also consisted entirely of Japanese adults, meaning that the importance of agreeableness and conscientiousness as social cues may differ across cultures.

Overall, the findings suggest that agreeableness and conscientiousness can serve as meaningful social signals that shape how people evaluate potential interaction partners and, in turn, whom they are willing to help.

The research “Personality Traits as Social Cues in Helping Decisions: The Roles of Agreeableness and Conscientiousness” was authored by Ryo Oda.