Fission & Fusion in Communities🪆
People talk a lot about building a new community, but rarely about how it evolves.
Communities are fundamentally groups, and groups aren’t static, they’re dynamic — constantly forming, evolving, fragmenting, and even breaking apart into sub-groups or new communities. So products that serve communities should make it easy for this evolution to occur.
Take group chats as a universal example. Someone starts a large Whatsapp group and eventually sub-groups break off unannounced — the original is unaffected, begins to decay, is paused, or dies.
With the right tools, it’s all fairly simple and elegant.
What is a fission-fusion society?
“A fission-fusion society is one in which the size and composition of the social group change as time passes and animals move throughout the environment; animals merge into a group (fusion)—e.g., sleeping in one place—or split (fission)—e.g., foraging in small groups during the day.”1
Humans form and live in fission-fusion societies. Fission is the action of dividing something into two or more parts. Fusion is the joining of two or more things to create a single entity. When fission or fusion takes place, it can be temporary or permanent.
Change in composition, subgroup size, and dispersion of different groups are three main elements of a fission-fusion society. Composition characterizes people in a group (e.g., homogenous vs. heterogenous), subgroup size describes the number of people (i.e., how large the group is), and dispersion looks at group distribution across space.
The overarching group is often called the parent group. Parent groups can break apart into smaller groups based on environmental or social situations that arise — whether often or just once, temporary or permanent. Distinct parent groups can also encounter each other, co-mingle, and emerge changed.
Fission-fusion societies are defined by a variety of these fission-fusion dynamics, also known as merge and split dynamics. It’s fascinating to think about how these dynamics translate to digital native or hybrid online communities — and how digital tools, products, and platforms can allow fission and fusion to occur.
Where do we see fission & fusion features in social products?
In this ‘very online’ world, we’re constantly creating communities and it’s common for people to belong to many at once. We create spaces and build walls, membranes, and gates to help communities organize and adapt to changing circumstances.
Since fission and fusion, whether temporary or permanent, are natural tendencies of communities, it makes sense that social products should reflect the same. Each combination has a unique use case and can map to unique product features.
1️⃣ Breakouts (Temporary Fission)
Fission is often temporary, where a portion of a group breaks off for a short period of time and later returns to join the parent group. These are breakouts.
Zoom has an explicit breakout rooms feature that lets you split a group into many distinct sessions. Interestingly, the DMs feature of feed-based social platforms can be a private breakouts feature (e.g. Twitter DMs). Comments features (e.g. on YouTube) let a subset of viewers have a public sidebar without really breaking off.
2️⃣ Spinouts (Permanent Fission)
Sometimes fission is a one-way, permanent action. When communities grow, become more heterogenous, or have inner strife, stability can decrease and eventually prompt fission. I think of this as mitosis or spinouts from the parent group.
Slack general channels often get too large for the conversation to remain focused on a narrow set of topics and pertinent to everyone included. When a subset of the group breaks off to start a new, persistent channel, that’s fission.
3️⃣ Mixers (Temporary Fusion)
Temporary fusion can be net new (bring together two unrelated, parent groups), or restorative (bring sub-groups of a parent group back together after separation, i.e. reversing temporary fission). I think of temporary fusion as mixers.
Clubhouse rooms regularly bring together people from different communities to talk for a limited period of time. Some of these communities may cross-pollinate more after regular mixers.
4️⃣ Mergers (Permanent Fusion)
Permanent fusion can result when two communities merge to create a new independent entity. Or, one community takes another in under its existing entity, which is effectively a migration or acquisition.
Facebook lets you combine two Groups or Pages, though with several constraints and some effort required to find out how. This is inherently a lower frequency need, reflected in how buried merger features are (when they exist).
How should fission & fusion inform network structure?
Until recently, we focused a lot on how large, legacy social networks like Facebook, Instagram, and Twitter effectively built single, giant communities with open social graphs. Users choose who they follow, but algorithms decide which “corner” of the graph — an implicit community — they end up in. These platforms have now reached the scale at which they’re facing functional and cultural challenges, many with community structure at the root.
1️⃣ Maximum Viable Community
Anthropologist Robin Dunbar theorized that humans have an upper limit to how many meaningful relationships they can maintain at once — about 150 people. In smaller groups, you can have stronger ties, and within larger groups, weaker ties.
Optimally functional communities hence have a theoretical maximum size or engagement threshold. Above this, they are likely to function less effectively and be unstable. I think of this as maximum viable community.
But, there’s a tendency for thriving digital communities, where physical constraints aren’t a factor, to continue to grow. There’s also a belief that Dunbar’s number may not hold true online or may be much higher. Usually, MVC isn’t top of mind unless scarcity or exclusivity is an explicit design goal.
If we believe that function declines at a threshold community size, then enabling community fission (and evolution) within large, growing communities, is extremely important. The likes of Instagram, Twitter, Facebook try to algorithmically introduce fission mechanics to mimic smaller communities, but this has been flawed and understandably is very hard to get right.
2️⃣ Small and Medium-Sized Communities (SMCs)
In contrast to such large ‘enterprise’ communities, we’re seeing rapid growth in the ‘SMB’ of communities, or SMCs — small and medium-sized communities. Newer platforms like Discord and Mighty Networks help anyone create small, closed online communities (perhaps aided by a backlash against legacy networks).
These platforms focus more on giving users the tools to build their own community — to be deterministic about group composition, size, and dispersion using in-built features. In some verticals such as gaming and crypto, SMCs created on these platforms dominate social.
The outgrowth of SMCs means people often belong to more than one community at a time. In the physical world, there’s a limit to how many groups we can belong to, but it’s much easier online (count the number of discords you’ve been invited to recently). Still, how many we can meaningfully contribute to is yet to be determined.
Having many small communities where the users have agency to determine how they are structured and run means more tools and features pertaining to fission are needed. When we belong to many at once, there’s also a good chance there’s overlap between them and a reason to engage across them, bringing up fusion dynamics.
3️⃣ Nested Communities
Nesting is one powerful tool for creating network structure by building a reliable relationship and bridge between parent groups and sub-groups.
Nesting can help alleviate challenges with intra-community growth (e.g., a group reaching a Maximal Viable Community threshold). Nesting across communities can be equally important (especially when we’re members of many), showing how groups relate to each other and simplifying inter-community engagement.
Slack and Discord are good examples of nesting within SMCs, primarily via channels. Reddit is a great example of nested community structure across a large, open network. “Subreddits” are clearly organized and it’s easy to jump between them. On Instagram, users can’t “zoom out” to see how communities relate or to choose where to participate.
Hence, nesting can be powerful both in large and small communities -- bringing structure, increasing stability, and helping optimize function.
How should fission & fusion impact social product design?
Social products should make it easy for communities to evolve like real-world social communities do. Fission-fusion dynamics are one framework we can use to think about how communities change — looking closely at group size, composition, and dispersion.
On balance, a growing, centralized community or network of communities needs to build more fission-oriented features. Complementary fusion-oriented features help reverse temporary fission as needed or bring independent groups together. Fission and fusion dynamics, both temporary and permanent, need to be considered in combination with network structure.
Community-based social products should be built to mimic fission-fusion societies. What makes this all the more prescient is the shift in momentum from a few large, online platforms to a more decentralized world — one where many small, digital communities can co-exist and thrive. As this happens, we’ll see an even greater need to help these communities organize around each other, connect, and communicate.