Skip to main content

The lizard brain — and email

The human brain has three parts. But I’m just going to focus on one part today: The lizard brain. This is the oldest part of our brain. It takes care of our basic needs like remembering to breathe. It is where fight-or-flight decisions are made.

Understanding the lizard brain is really important if you’re writing emails

The lizard brain is the part of the brain that decides to open and read an email.

The lizard brain is the first responder. Imagine you’re crossing a busy street and you hear a car sound its horn. Your lizard brain causes you to turn in the direction of the noise. Your lizard brain helps you decide “Am I in danger”? This time, it’s safe.

Which part is the lizard brain

The lizard brain is hard at work when you’re scanning new emails in your inbox. The subject line “Account overdrawn” from your bank will probably set off alarms in your lizard brain. You should probably open it, read it and get that resolved.

But most companies like yours and mine will rarely be delivering messages of great urgency like a bank account being overdrawn.

And sending messages designed to alarm users into opening them gets tiresome quite quickly.

How should we stimulate the lizard brain?

Beyond responding to alarms, the lizard brain is also curious.

The lizard brain (when not sensing danger) is stimulated by the new or interesting.

Here’s an example

A dating tips mailing list (I sign up for A LOT of newsletters) sent me an email with this subject:

What never to say to a woman

My lizard brain couldn’t resist that email subject (even though I’m happily in a relationship).

But that’s just the subject line, what about the rest of the email?

I’ve found that a great way is to structure emails is to use a technique created before email by the wizards of direct mail. When you write emails, structure them emails using A.I.D.A. That stands for:


You’ve got 2 seconds to capture and hold the lizard brain’s attention. Use the subject line and the first few lines to suck them in.

“The human brain has three parts” is an example first line that captured your attention


This is where you educate the user and share the details of the email. Make sure to focus on the benefits to the reader. Don’t spend the whole time talking about you!

If you’ve made a feature update, talk about benefits of those features in the “interest” section.

If you’re trying to recruit people to an event, show them why they should go to the event and give them details the event – where it will be and when.


Write at least one line to build up to the action you want the reader to take.


  • “Your clients are going to personally congratulate you on the improvements we’ve made in this release”
  • “Tickets are going fast, and will increase by a dollar each day until they’re all sold out”


Try your best to limit what you’re asking people to do. Stick to one action per email.


  • “Log in and see the changes”
  • “Reserve your spot today”

I can’t wait to show you some of the emails I’ve written using AIDA.

This week see if you can stimulate some lizard brains.

Take a look at one of your emails and rewrite it by breaking it in to Attention, Interest, Desire and Action.


P.S. For 3 people who reply (before Monday) with an email broken down in to AIDA, I’m going to buy and send you a copy of “Ogilvy on Advertising”. This is a MUST READ if you want to stimulate lizard brains with compelling emails and website copy.