Companies know that there is power in default choices. When you sign up, they default your choice to agree to receive advertising emails from them. They also default to the option that your contract will renew at the end of your subscription period. Whenever possible, they make the choices for you (repeat last order? same credit card?). They do this because they know that overcoming the default takes work – even just un-clicking a single box – and that tiny bit of work is enough of a barrier that some people won’t do it. A tiny bit of effort can cause a tiny percentage to change their behavior and over time and large populations, the difference can be huge; at the scale of online retail, “a tiny percentage” is a lot. There’s money to be made in defaults.

It’s not just companies who have their defaults. You have defaults too, only you probably didn’t design them quite as purposely. You probably have a certain brand of toothpaste that you always buy, for example, and it’s easy to just keep buying that same one rather than making a new choice each time. You probably shop at the same supermarket, drive the same way to work, and order the same thing at your favorite restaurant. These are defaults of the mind, of your habits, and they are hard to overcome because they are easy, they don’t feel like they are causing any harm, and because you probably don’t even notice them.

Think of it this way: your mind has a barrier at the entrance, blocking passage to new things. You don’t just allow anything in, it has to get over that barrier. The default gets a boost – maybe big, maybe small – while non-defaults have to get over the barrier without any help.

I was lying in a hospital bed, and a doctor came in. 

Quick – what kind of person did you imagine as the doctor? Were they male? Female? Black? White? Did they walk in, or roll in with a wheelchair? Whoever you imagined – that’s your default concept of a doctor. That means that anyone else has a higher barrier to overcome to be matched to your concept of “doctor”. If they don’t fit your default, your brain is more likely to guess something else – nurse, tech, janitor, hospital administrator – some role that, in your head, more closely matches your mental default.

But hey, besides a little bit of awkwardness, what’s the harm? Just one time, for a split second, probably not much. But consider lots of individuals with lots of defaults, and how that can affect whole classes of people over time. Or what if you are on a medical school admissions committee? Or you’re a casting director finding someone to play the role of a doctor? Or you’re deciding which primary care physician to choose for your parent? In each of these situations, your default comes into play, making things a bit easier for those who fit your concept and a bit harder for those who don’t.

We all have these differential mental barriers. It’s not because you’re a bad or thoughtless person – it’s just the way people work. It’s easier to have mental shortcuts than it is to go through life without any expectations.

Defaults are not only about toothpaste or people, but also ideas. An argument that supports what you already think doesn’t have to do much to gain access to your mind. You probably even seek out and experience a feeling of relief when you read something consistent with what you already believe. But a different idea has some work to do. Not only does it meet the full barrier to entry, but even if it enters your mind, it makes you feel uncomfortable. It’s easily ousted again in response to a more comfortable thought.

Defaults are helpful, because they let us live without having to make similar choices anew each time. There’s enough to think about without having to question all of our assumptions, after all, and we’re more efficient if we can generalize. But defaults are also dangerous, because it means that some people, ideas, and things have may have a free pass into our minds, while others are stopped at the gate. We may be missing out on something great, or letting something dangerous in.

With the world in its current state, it feels like we’re being hit with new things every day. How do we choose what to believe and what to doubt? In a changing world, it’s dangerous to cling to your old defaults without question. There’s a whole world out there of challenging ideas, different people, and perhaps even new toothpastes. You’re going to have to give them a boost if you want to give them a fair shot.