How should you behave if you want a new acquaintance to like you?

"When meeting other people for the first time, how should one behave if one's goal is to be liked?"

This was the question behind a new study on young adults in Germany. Michael Dufner and Sascha Krause at the University of Leipzig wanted to explore what leads to popularity (being generally liked by others) and also 'unique liking' — where one person likes (or dislikes) a specific other. As the researchers write in Psychological Science, "Both kinds of being liked are important for theoretical and practical reasons." Popularity is important for mental health and wellbeing, while 'unique liking' (which research shows is typically reciprocated) can lead to friendships, partnerships and romantic relationships.

The researchers focused on two types of behaviour: 'communal' and 'agentic'. Communal behaviours include being polite, warm, friendly and benevolent. Agentic behaviours include being leading, dominant, confidant and boastful.

A total of 139 students who didn't know each other were initially put into small same-sex groups. Each student introduced themselves to the others, talking briefly about where they were from and their favourite leisure activities, for example. After this, the participants indicated how likeable they found each of the others, and also how much they'd like to get to know them. These responses were used as baseline liking ratings.

Each student was then paired with each of the others in turn, for five-minute 'getting acquainted' conversations about topics of their choice. After this, they gave fresh liking ratings for the others in the group, and also indicated whether they would like to be friends with them.

The researchers had videoed the conversations. This allowed them to rate each participant on a range of communal and agentic behaviours. Dufner and Krause then compared these results with any changes in how much the others liked them.

They found that participants who had shown higher levels of both communal and agentic behaviour were more popular: that is, they were generally considered more 'likeable' by the other participants.

The results for unique liking were more complex. The pair found that when a person showed more agentic behaviour towards their partner than was typical for them, this was linked to being disliked by their partner. ('Typical' refers to the norm for that person during all of their conversations.) However, when a participant showed more communal behaviour during a conversation than was usual for them, they were particularly well-liked by their partner.

Of course, the participants had no clue about each other's typical levels of communal or agentic behaviour with a new acquaintance. But deviations from these norms did still affect unique liking ratings. What caused the deviations? "It must have been the unique constellation of attributes of the actor and partners," the pair writes.

This study doesn't reveal what those unique constellations might be – that's something for future work. But the researchers suggest that, for example, someone with a strong motivation to feel powerful might, on meeting a partner that they perceive to be insecure, ramp up their agentic behaviour to dominate the conversation. "Potentially, the insecure interaction partners felt increasingly uncomfortable and then uniquely disliked these actors," they write.

Why might someone show unusual levels of warmth and friendliness towards a specific partner? Such behaviour might have been driven by the partners agreeing with each other during their conversation (something that the researchers didn't look at). Perhaps this agreement led to the partner's increase in liking ratings, rather than the heightened communal behaviour per se, or perhaps both played a part.

Clearly, more work is needed to understand what underpinned the results. It's also worth noting that the participants were all young adults living in Germany. These results may not generalise to other cultures or other age groups.

But, for anyone whose goal is to be liked, the team argues that there are a few general lessons from the study in how to behave. When it comes to communal behaviour, whether you want to be popular or make someone your friend, the advice is straightforward: "Be as communal as you can!"

Displaying agentic behaviours, such as confidence or even dominance, also seems to be helpful if you want to be popular. But if your goal is to win over a specific person, be careful. "Even though agentic behaviour might generally make one popular, it might not be good advice to show a higher than usual level of agentic behaviour when trying to win a new friend," the researchers advise.

"We hope that these recommendations are useful for navigating through everyday interactions," they conclude.