How does trust work?

Last updated on 11th June 2021.

Trust is the foundation of healthy work relationships. Team leads need to gain the trust of individual contributors, who, in turn, need to trust each other and the company leadership. Without trust, the organisation descends into politics, secret meetings, and backchannels and it all just becomes so stressful.

So what is trust? Why do we trust some people and not others? How can I get more trust? How can I fix trust issues in a team?

It turns out a fair amount has been written about trust in the management and psychology literature

. I'll try and summarise what we know about interpersonal trust.

Trust encourages vulnerability

Interpersonal trust is how willing the trustor is to make themselves vulnerable to the actions of the trustee, with the expectation that the trustee will behave in a particular way, even without the trustor watching.

For instance, when you, as a team lead, delegate a piece of work, you put yourself in a position of vulnerability to the IC you are delegating to by giving away the responsibility for a task, but keeping accountability (i.e. you look bad if the task is done badly). The expectation is that the IC will do a good job.

Similarly, when an IC does a task you delegated to them, they put themselves in a position of vulnerability (they use their time to do something you ask them to) with the expectation that, if they do well, it will be recognised: you will make sure they get the credit, or that it contributes to their performance assessment or whatever matters to them.

What makes you trust people?

The most commonly accepted model of interpersonal trust is the ABI model. It suggests that you trust individuals based on their perceived ability, benevolence, and integrity.


You need to believe the person you are trusting has the competence to help you. When you delegate a piece of work, you need to trust that the IC is able to do a good job. Similarly, the IC has to trust that you are able to reward them in ways that are meaningful to them.

Trusting ability is domain-specific: you might trust an engineer with a specific task, but not a designer or vice-versa.


Benevolence is the belief that the trustor will do good for you, even if there is nothing in it for them. For instance, you're more likely to trust someone who consistently gives you credit for good work.


You trust someone's integrity if:

  • they consistently obey a set of principles
  • those principles are acceptable to you

When you assess someone's integrity, you base it on:

  • personal observation of their actions, of how consistently those actions obey a set of principles, and of how the actions match what the person says
  • what other people tell you about this person's principles and actions

The difference between integrity and benevolence is that integrity applies to someone's actions in general, whereas benevolence applies to their actions towards you.

For instance, as a team lead, you are more likely to trust someone who you think works hard, is dedicated, is going to do their best to do well, and will take feedback well.

Similarly, an IC will trust you when you delegate a task to them if, in the past, you have consistently supported them or other ICs, if you have reflected credit onto them, or if you have helped them or other ICs grow or improve.

How can I use this?

Trust issues are hard to talk about, because trust is so associated with vulnerability. Having a mental model of trust and a vocabulary to talk about my problems trusting a colleague help engage with trust issues in a more constructive way.

Related notes