There are clear benefits to keeping teams small. The agility of the team and the ability to communicate between members becomes increasingly difficult with every new addition. With that said, a team too small risks having a narrow field of view, lack of wider experience, and a higher level of dependency on each person.

Over the years then, even the biggest in tech have invested time and money into researching ideal team structures for their operations. Companies with hundreds and thousands of technical roles continue to focus on crafting small teams working in sync for the benefit of combining experience with the ability to operate effectively and pivot quickly in response to the likes of product feedback and changing business requirements.

So, is there an ideal number of people to have within a team?

There’s no magic number

In short, no; there’s no perfect number of people to have in a team. Your requirements are unique and in some instances, a team of three could be more effective than a team of thirty. In other situations, the inverse might apply.

Many who have worked in technology and particularly in development teams in the past will likely be familiar with a team size of, give or take, seven. Iterations of the SCRUM guide have recommended a team size between three and nine, for example. This size gives a balance of having senior experience and leadership within the team, additional supporting yet experienced roles, and space for more junior and learning positions.

This team has an overall focus – ownership of a system area for example – and each role plays a part in the delivery of their focus, with other teams working in parallel with the same structure and a different area of focus or ownership.

With an understanding of how small teams can be most effective, let’s take a look at some of the psychology as to why.

The role of Miller’s law

Miller’s law, originally titled ‘The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information’. is one of the most highly cited papers in psychology. The study behind it, published in 1956, understandably has no reference to technology teams, but its findings continue to apply and it plays a role in how many of us continue to build and operate teams today, either consciously or subconsciously.

In simple terms, a person can typically retain somewhere between five and nine pieces of information in short-term memory, seven being the median. Information beyond this range is more likely to be forgotten or impact the recollection of other pieces of information.

It’s often referred to as 7+/- 2 and a common place to Miller’s law at work is in meetings and in particular, daily standups. In a standup, each team member quickly gives an update on their previous day’s work, plans for the day ahead, and any potential impending challenges for the rest of the team to provide insight and support on. As a team increases, so does the duration of the meeting and the amount of information to process, which becomes increasingly difficult to retain and some is inevitably lost.

It could be argued though that in today’s hybrid and distributed landscape, many tech teams live and die by the likes of Slack and Notion for day-to-day notes and communication, creating a simple paper trail meaning this information doesn’t always need to be committed to memory. Does this mean that the theory of seven no longer applies?

There’s certainly a case for it, but here’s a hypothetical for those in larger organisations: when it comes to comms, have you found that you’ve had to mute the larger channels or conversations, opting to only receive notifications from smaller ones? Furthermore, have you ever found yourself overwhelmed by the number of discussions happening in parallel through multiple channels and team chats?

Chances are, the busy channels deliver information thick and fast, where some is relevant and some isn’t. That non-relevant information takes up valuable storage in your short-term memory and takes time away from you doing your best work. Subsequently, you block it out.

The smaller channels, on the other hand, are likely where updates have more direct value to you. They likely consist of some or all of your team members, plus some key stakeholders and thus Miller’s law comes back into play – the smaller team discussions bring more value to you and you’ll likely find that you retain more of that information.

The real-world convenience

Miller’s law is psychology from nearly 70 years ago. It’s also very general. There is the wider belief that when a team is experienced and focused on a single field, such as a technology or development team, the number of team members can surpass the 7+2 rule and continue to work highly effectively, as the objects stored in a person’s short-term memory are related to each other and to the person’s existing knowledge.

We’ve also highlighted how today’s technology can make communication much more efficient between a larger group of people. Finally, there’s also the fact that team size should consider more than a person’s short-term memory capacity, so is seven, give or take, still a useful figure?

As we’ve covered, a team that works within that seven, plus or minus two, can:

  • work effectively and efficiently, working in sync with other teams, but focusing on their own area of responsibility,
  • group a range of roles with diverse experience, allowing seniors to lead and juniors the opportunity to be mentored,
  • demonstrate a clear path of progression for the members of the team,
  • give the business the ability to quickly steer the focus of a small number of people as needed,
  • make measuring output and other key metrics at a more granular scale, achievable.

A key component of Miller’s law is the give or take. Over time, you may wish for your overall technology team to grow – with the correct processes and structure, you can with relative comfort scale any single team, or sub-team, to up to nine people. A tenth hire, should they join your business, then gives you the ability to divide the existing team of nine, into two teams of five and remain within the seven, plus or minus two, range. Whilst dividing any team requires careful consideration, you can be confident that the overall structure you have created and the principles of Miller’s law will apply to both.