System 3

If System 1 is fast, automatic thinking…

and System 2 is slow, deliberate reasoning…

…where does imagination fit?

That’s what University of Michigan researcher Milena Stepanova explores in a recent paper.

She’s not the first to raise it. Behavioural economist Leigh Caldwell (among others) has been pointing to a third system for years.

So, let me introduce System 3, a reflective process where we:

• mentally simulate the future

• factor in identity (“who am I / who do I want to be?”)

• use emotion as valuable input

I notice this most in a changeroom.

System 1 might draw me to an item.

System 2 might rationalise the purchase.

But something else is happening.

I’m imagining what I already own that it works with.

I’m picturing where I’d wear it.

In other words, I’m simulating the future.

That’s System 3.

As Stepanova puts it, it’s “slow and deliberative, yet unconscious and emotionally grounded”.

Why this matters in business:

• Customers don’t buy products – they buy future versions of themselves

• Data doesn’t change behaviour – identity does

• The best decisions aren’t purely rational – they’re aligned to who we imagine ourselves to be

Has System 3 been empirically established? 

Not yet.

But I think there’s enough credible argument to justify its consideration in our models of decision-making and behaviour.

System 3. Just imagine.

Ref: Stepanova, Milena. (2026). System 3 Thinking: A Conceptual Expansion of the Dual Process Model for Complex Human Decisions. International Research Journal of Multidisciplinary Scope. 07. 864-873. 10.47857/irjms.2026.v07i01.07960. 

🌟 If you found this interesting, let me know! Buy me a virtual coffee ☕  or forward this email ↗️  to someone who also might like it. Your support means I can keep sharing ideas about behavioural science for free.

🧠 Learn the science of Influencing Action

Hey, are we connected yet?