Published on June 21, 2025 7:59 PM GMTJohn Wentworth recently posted a discussion-inducing piece about how the willingness to be vulnerable is core to romantic relationships. This is not obvious to me as the core thing. I think romantic (and other) relationships are arguably about intimacy[1]. Perhaps intimacy always requires vulnerability? To answer that, and because it's generally interesting, here is a babble[2] of the kinds of intimacy:Physical Intimacysexual intimacy[3]non-sexual physical intimacy (cuddling, touch)Intellectual Intimacythe intimacy that results from the exchange and sharing of ideas and/or doing cognitive work togetherintimacy that results from having the same knowledge or beliefsthink of the connection that arises from having read the same book as someone elseEmotional Intimacyrevealing emotional states to each othersharing emotional states (getting in sync somehow, sharing of emotional stimuli)Values Intimacywe have an intimacy born out of knowing we care about the same thingsPreferences or aesthetics intimacyliking the same things. Often instrumental towards sharing experiences. (Overlap with values intimacy.)Experiential Intimacysharing experiences with someone, e.g. travelling together, watching movies together, etc., but especially intense or difficult experiences like fighting in a war together, running a startup, having a child, experiencing severe illnesshaving had the same experiences as someone else, even if not had together, e.g. the intimacy of having both grown up in the same place, both being raised Christian, etc.People often experience a kind of intimacy from sharing the same hobbies or fandom which I think has elements of both values intimacy and experience intimacy (we like the same thing and have shared experiences of doing it). Vulnerability[4]/Trust intimacyI feel close and intimate with you either because I trust that you won't hurt me even when given the chance to do so, or in fact I have observed that you don't.Or in fact there is intimacy in something we are presently doing because doing it with you makes me vulnerable and relies on trust.I think emotional disclosure (which is often disclosure of facts of high emotional significance) creates feelings of intimacy due to the vulnerability:(1) I might be disclosing something (e.g. I had a fight with my husband yesterday) that I don't want broadly known, so I'm trusting you to not share.(2) Your reaction (judgment) of the matter will have emotional consequences for me, e.g. if you are dismissive vs supportive/validating vs invalidating, and in sharing I create the possibility for you both to make me feel better or worse, and this is vulnerable. See[4] Investment intimacywe are both invested in the same venture, e.g. business, project, community, childCommitment intimacyrelated to investment intimacy but the commitment is to the relationship itself, e.g. married people have this kind of intimacyexclusivity (e.g. monogamy) is a kind of commitment intimacy"Being seen or known" intimacyanother person having deep and good models of you, usually of your emotions (see emotional intimacy) but also beliefs, values. I think this creates feelings of intimacy from a few angles:someone getting to know you well is them making an investment in you and indicates they value youoften the reason to know someone well is so you can optimize for their preferences or wellbeing, so it's an investment suggestive of caringbeing well known by someone and still liked is more secure than only being shallowly known. It precludes the risk that they'll find out something and stop liking you since they already know youand naturally "being seen and known" is having someone share your experiences, the arch-intimacy of shared experiences"Unique connection" intimacyA feeling of greater connection to someone when you have something in common that not everyone else does, e.g. a particular background, experience, value, etc.E.g. two Earth-humans in a cosmopolitan universe bonding in an Andromedan bar over how much they miss 9.8m/s² gravity and 20.95%-oxygen air."being special together"Communication intimacyI'm thinking of things here like sharing language and concepts that make it easy to communicate closer to your own native thought language. One of the things that made me feel able to connect with my wife early-on, compared to many others, is she was fluent in LessWrong and CFAR concepts. This kind of intimacy will naturally arise from having had a similar background or present, e.g. being raised in a similar way, studying the same topics, etc.Playfulness Intimacy (also sense of humor intimacy)play is a thing that humans and other creatures do. Different people play in different ways such that there's an intimacy in having compatible styles of play. I think compatible senses of humor are a major one here, e.g. two people might have an intimacy born of enjoying making the same kinds of puns or doing countersignaling teasing in the same way. I'm struck that arguably many of these forms of intimacy are just variations on experiential intimacy: having the same experiences as another, or by extension the same knowledge as others. Sex is an experiential activity you do with another person, but so is sharing ideas or your emotions. Someone who shares your values and beliefs likely experiences the world in similar ways.A possible underappreciated challenge for significant age-gap relationships is that life experience can be pretty different. The older person might have experienced a range of experiences the younger person is yet to, but also experiences both went through (e.g. childhood could be quite different, for example if one person had the internet and smartphones growing up and the other didn't). Of course there are many other ways for life experience to have diverged a lot, e.g. having grown up with very different socioeconomic circumstances.Though I've mostly focused on romantic intimacy, it's illustrative to think about the intimacy people feel with family members, e.g. siblings. The connection is unique and exclusive (fixed) in that arbitrary people cannot become blood siblings even if people like to speak of siblinghood symbolically. Culturally, we implicitly assume commitment to family members. Then any siblings you were raised with will have tremendous shared experience: where and when you grew up, education, values you were inculcated with, having the same parents.Maybe we can divide intimacy into trust-intimacy and understanding-intimacy. Commitment, investment, and vulnerability are the former. Emotional, intellectual, and other forms of experiential are the latter. Values plays into both. Trust-intimacy is very helpful in building understanding-intimacy, because giving you knowledge of myself often means giving you greater ability to hurt.That said, I think it's likely possible to build a lot of intimacy without doing the kind of vulnerability that John points at from Truth or Dare. I think fighting on the frontlines will do. I think having intense sex will do it. And many other things that are having shared experiences or discovering past common experiences, values, beliefs, language. And yet, I could also see the case that those alone would never be enough for the basis of a really solid long-term intimate romantic relationship. I reckon many people (perhaps myself too) have catastrophically failed to realize that intimacy of one kind doesn't necessarily imply other kinds of intimacy. I think this should be kept in mind because I think commonly we connect with new people over one or two forms of intimacy, and then can falsely assume that those imply other kinds of intimacy will exist.And while I think it's possible to have a relationship with all the kinds of intimacy, my guess is it's rare to be maxed out on all of them at all times and you'll often want to compromise somewhere, perhaps factoring intimacy desires across different relationships, perhaps merely prioritizing.Lastly, I think it's funny how contextual and relative intimacy and connection are. The Andromedan bar bonding of missed gravity is fictional, but there are plenty of non-fictional instances where what in one context is insufficient commonality for connection is enough basis in another, e.g. expat communities. Maybe just as personality arises from a negotiation between the individual's traits and society, the intimacy felt between two people is a function of their individual traits but also the context they're in. The impact of dating apps on courtship could be seen from this angle – the ability to feel intimacy is eroded because the context is so much different from one's previous smaller network and environ.I'm rambling here and don't have a particularly punchy point to end on. Of course "sixteen" title is meant playfully. Interesting to break it down though.^The close synonym I could also use here is "connection".^Aiming to be comprehensive rather than factor intimacy into non-overlapping independent components. ^The degree of intimacy of sex is affected by the presence of absence of other elements on this list, e.g. it is more intimate if if it is exclusive, it is more intimate if it involves non-standard acts that are a rare common interest of the participants, it gains an element of intimacy if there's vulnerability (risk) via the risk that either party might defect and disclose the encounter when this would have undesired consequences.^I'm fond of the definition of vulnerability that you've been vulnerable when you've shared something such that if the other person were to laugh, it would hurt you. Crucially, vulnerability is not as simple as sharing relatively personal facts.Discuss