Is your appearance (i.e. face to face meeting or video) necessary for a friendship? We said no. You can develop a friendship via other means (telephone, letter, email). If the appearance gets added in later, it can sometimes cause surprise or a feeling of disorientation, as I described when I first met my email/phone friend Janice Hardy face to face.
Is friendship a commodity? Sometimes it can seem that way. It appears also that Middle Grade fiction requires the author to take a stance on friendship.
Tight narrow age groups, such as in school grades, tend to restrict friendships. Siblings can cause you to make friends across age groups. These restrictions relax once you are outside of a heavily age-stratified social environment.
Who are you allowed to be friends with? This is an interesting question, because lots of people try to restrict their children's friendships on the basis of various factors such as race, class, gender, or even caste. Can men and women be friends? Of course they can - the very asking of that question reflects negatively on the beliefs of the person asking it (I'm looking at you, Harry). Sometimes you can feel forced into a friendship because your parents are friends with someone else's parents - or sometimes those friendships can become an unexpected gift.
In some cultures, there is a sense that neither of the two members of a friendship has higher rank than the other. In others, that is not the case. France has the formal and informal pronouns vous and tu, and they used to be used based on status even within a friendship, but the criteria for their use have changed and now are more indicative of solidarity rather than rank. Japan has the concept of senpai and kohai, which usually indicates age or year in school. The senpai is older or more experienced and has things to teach the kohai.
Sometimes people try to control their friends by making them compete for favors.
Can you be friends with a parent or a direct caretaker? Perhaps, or perhaps not, depending on the cultural definition of a friend and the nature of your relationship. Maybe, as in some cultures (e.g. a culture in the Kalahari), you can be friends with your grandparent before you can be friends with your parent, because it skips a generation. The degree of control that the parent is expected to exert over your behavior has a lot to do with the answer to this question.
How well do you keep in touch with friends? Can you be friends in one context and not in another? What kind of contexts?
What can you discuss with a friend? Are there topics (like politics or religion etc.) that you avoid in order to keep the friendship? How much trust do you have? Do you feel safe with your friend? What can you talk about without suggesting romantic interest?
You can create an echo chamber in a group of friends who all agree. At the same time, this can be a safe place for people to air their feelings. Whether it's potentially harmful depends on the link to evidence.
Sometimes friends can argue about things they agree about, exploring nuance or carefully defining terms.
Where can you talk with friends? Hallways? Stairwells? Restaurants?
Do you live with friends? How does that change your relationship? How do politeness expectations differ? How do you negotiate the maintenance of your shared environment? Is there a place you can go if you have to be alone because you can't stand it any more? What impact does that have on the others?
How do you get your basic-level psychological needs met in a friendship?
Do you have an obligation to air grievances against a friend? Some friends expect each other to "read minds" and have the other person notice that they are disgruntled. This can lead to friendships breaking up.
Power and money complicate friendships.
Would friendships be stronger in an empathic or telepathic society? Would they be fewer?
I talked about the question of friendship in my story "Cold Words." Because rank is so important to the alien Aurrel, the alien protagonist Rulii has great difficulty understanding the word friend and struggles with his relationship with the human Parker throughout the story. Each one has things to offer the other, and each one admires the power of the other, so neither one wants to take a dominating stance. It makes Rulii feel as though the relationship is uncomfortably intimate. The Aurrel define the relationships of "huntmate," a person who shares a goal or project with you, and "littermate," a sibling, and "consort," or boy/girlfriend/spouse.
Needing companionship is adaptive, because people can survive better in groups. Vulnerability is important though it also can cause trouble.
There are friendship bonding rituals and procedures. How would another society define those?
Do friends have nicknames for each other?
Thank you to everyone who attended. Today I'm interviewing guest author Marshall Ryan Maresca about his new book, An Import of Intrigue. Next week on December 14, we'll be discussing in-groups and how they are defined, and what kinds of names and habits they have to mark themselves. Join us!