On 30 July is Friendship Day. In an interview, personality psychologist Prof. Dr Franz J. Neyer explains what friendships are, what transformations they undergo and what friendships between countries, cities and universities can look like.

Professor Neyer, what is friendship? What defines friendship?
Friendships are voluntary, informal relationships with people who are around the same age. And they usually have a positively valued quality. They are also based on mutuality – or reciprocity, as we say – so that give and take are balanced in the emotional, but also in the instrumental sense. They usually do not involve open sexuality and can be distinguished from partnerships in this respect. They also differ from kinship relationships or other relationships between unrelated people, which are more formalised in character, i.e. defined more by social roles such as supervisor, employee, doctor, etc.
Aristotle described friendships as relationships among equals that are based on voluntariness. That is what makes it special. They are relationships beyond family, neighbourhoods or hierarchies in a work context.
How important are friendships for us human beings?
Friendships are important for personality development, especially in adolescence. They offer intimacy and familiarity to young people. As a rule, young people have more personal exchanges with friends than with their parents. They thus serve as means of detachment from the family of origin and thus for the development of one's own identity. And they possibly prepare for later partnerships. This is the developmental psychological function of friendships in adolescence.
However, friendships are also important throughout life, they only decrease quantitatively from young adulthood onwards. So as adults we have fewer friends than as teenagers or as young adults. This has to do with the fact that people become more selective in their choice of friendships in the course of their lives. Only a few remain, but we may know them for decades and they provide emotional and social support. If you think about old age, friends can also compensate something, for example when the partner is no longer there. Then friends can also fulfil existentially important functions again.
Are there concrete figures on how many friends you have or should have on average?
We did a meta-analysis on this and saw that the average numbers vary depending on age. But they vary quite a lot from one individual to another. I think communicating such numbers without the exact context would lead to misunderstandings. For example, someone who has 800 Facebook friends would just have 800 online contacts, which should not be called friends. I think a handful of good friends or a little less, that's already very good.
Then there are also good and not-so-good friends. There are friends who are closer to you or not that close – there is a considerable variability. And it always depends on the personality. I approach the topic of friendship from the perspective of a personality psychologist. And people who have a higher connection motive, that is, a higher motive for social contacts, may have more friends than others. Others may need just a few friends.
Therefore, you can't say in general how many friends one has to have. Each person has to find out for themselves. In any case, a person who has no friends at all is missing something in life, especially in adolescence. In particular, young people without friends are missing a milestone in their development, which is really a cause for concern. But whether someone has three, five or ten friends, doesn't matter.
What's the best way to make friends if you don't have any?
You don't have to look for them actively, they are usually just there. You make friends where you are: at university, at school, in your peer group. And there's a rule: Birds of a feather flock together. And when you're at university, you automatically meet people who are like you or, in other words, have comparable or similar interests. That doesn't guarantee that you'll become friends with them, but it does prepare the ground for it.
Similarity in terms of age, gender, education and to some extent personality plays a role. Studies have shown that it is not so much the objective similarity that matters, but rather the subjectively perceived similarity. You feel you are of the same ilk as the other person, and that is why there is this attraction. So "Birds of a feather flock together" is definitely more true than "opposites attract". And the same is true in the dating context.
You already said that friendships are changeable. Can friendship also become enmity, or when should one end a friendship? Or in other words: How can an enmity become a friendship?
The latter question is particularly interesting here in Jena, when you consider the friendship between Schiller and Goethe. At first, there was no love lost between them, and Schiller made very disparaging remarks about Goethe before they became friends eventually. This occurred in part because they overcame their rivalry and competition. Despite their shared intellectual interests, they were prepared to recognise and accept the differences between them. Schiller later said of this friendship that it had the character of love. Both overcame their enmity, rivalry and mutual scepticism and became friends out of a spirit of freedom. Their friendship is one of the most important in German intellectual history.
So a transformation from hatred, rivalry and mistrust towards love. These are powerful emotions.
In principle, friendships are less stable than kinship relationships, parent-child relationships or sibling relationships because they are very much based on the reciprocity rule. If the give and take no longer works and conflicts arise because of this, friendships get terminated. Family relationships can tolerate such things more easily and usually do so. Then again, there are other problems.
But friendships are not simply abandoned. Sometimes you just get out of touch with each other. This has to do with the fact that you have to fulfil changing tasks in life, such as starting a family or starting a career. That changes the social network. Many young adults, like our students here, are under a lot of pressure to be mobile. They have their local friendships, but may have to move to another place to find a job. Then they lose sight of each other. But some friendships endure – and those are the particularly important ones that can be maintained across distances.
And last for years, over a longer period of time.
Exactly. There are also breaks every now and then, and then you get closer again. But of course these are relationships that have to be nurtured because they are not a given, like family relationships. Friendships are acquired and because they are voluntary and reciprocal, they have to be nurtured.
What does that mean in concrete terms? How do I maintain a friendship?
By always seeking contact, initiating personal meetings and maintaining the exchange. In itself, this is quite simple and banal, but in fact it is not. You have to do something for it.
So it's not only about communicating my emotional state, but also about asking the other person how they are doing and really being able to exchange ideas on both sides. This brings me to the next question: When does one realise that a friendship is no longer a friendship or perhaps one should end it because it is not doing you any good?
We don't know if it's really true that friendships can't do you any good. I think the general case is that you just lose sight of each other. We deliberately end friendships when there are serious conflicts or serious grievances that cannot be overcome. And then it is also a kind of liberation. Then you break away from a relationship that has become a burden or a kind of obligation and where the voluntariness and joy of the relationship no longer exist. And then one should and can also end it, of course. That is part of the essence of friendship. This is more difficult with family relationships.
Of course, it is also possible with family relationships. But ending even extremely conflictual or unbalanced family relationships is very rare compared to friendships. Think of parents and children, for example: how much do parents invest in their children without getting anything back? If it goes well, they might get something back at the end of their lives when they themselves are old and the children take on a different role. That's what the intergenerational contract says, or maybe that's how the principle of deferred reciprocity works. But we don't see anything like that with friendships. Except when they become so intense, so intimate, that they have the character of an elective kinship.
But if things are not going well, if the conflicts are rampant and cannot be overcome, what would you say: should one deliberately let it fizzle out or should one consciously confront? In short, should one try to speak out?
Yes, in close relationships you should always be ready to confront each other and not shy away from conflicts. Conflicts can also lead to people coming closer together again and overcoming a distance or a hurdle that exists between them. Research shows that you can grow from conflicts. I would always advise that. However, I am not a friendship coach, I am a scientist. Everyone has to find that out for themselves in life.
It seems that friendships are something very personal. But can there also be friendships between cities, countries or universities? The other day, Israel called Joe Biden the best friend Israel has ever had. How can that be? Do such friendships exist or is that impossible?
I have now only discussed friendship as a personal relationship that is not defined by social roles, but by the personal history of those involved and the personalities they bring to the table. When friendships are formed between cities, institutions or countries, it has a completely different dimension. Then it is certainly voluntary on the one hand – but on the other hand, such institutional relationships are based on a system of contracts. There are rules that have to be adhered to in order for it to work. And it could also be that if these rules are not observed, these friendships will also become obsolete or terminated, I assume.
But I would not go so far as to transfer the rules of friendship between persons to friendships between groups or countries. As a relationship researcher, I can't say what it's like between countries or between cities. You would have to ask sociologists or political scientists. But I know that the concept of friendship is also used there. Probably because it is also meant to associate and signal a positive relationship based on voluntariness. But I would think that the explicit set of rules is much more important than in the case of a personal friendship. Because in the latter case, the set of rules is more implicit.
Such university partnerships or friendships are characterised by an exchange of students who often cross national borders. On the one hand, it's about numbers, i.e. how many come and how many go, so that it stays balanced. But on the other hand, lifelong friendships may actually develop along the way.
Exactly. Of course, everyone must have a benefit. But that also applies to friendships as personal relationships: there must be a benefit for both. And that is the case when there is reciprocity. But this can also be shown for partnerships. Relationships are stable when a lot has already been invested – not only materially, but also emotionally – and when there are no attractive alternatives. And this is probably also the case with institutions.
That means, if a potential friend comes along who offers me more, I end one friendship and start the new one?
Yes, that could be the case. But you don't sit there and calculate it in a rational manner - of course that's not the case in relationships. What matters there is the subjective perception of the benefit. And that is not calculated in euros or the like, but in emotional and social "currency". It's the same with partnerships - naturally. It's not just about it being great all the time and the partners floating on a pink cloud. It's about what you have invested. Partnerships are more stable when there are children, for example.
What else would you like to add?
It depends very much on personality how friendships work – by seeking out friendships, shaping them and contributing our personality. And especially with young adults – this has already been shown in other studies – it is the case that the personality does not change much at all through friendships. Conversely, how friendships develop over time depends on the personality. In other words, it always depends on ourselves.
Title image: Marco Körner / University of Jena