By now most people understand that we humans aren't always rational.

We senselessly procrastinate, ignore solid information that doesn't square with our core beliefs and retire to Arizona only to learn we don't like the desert sun after all.

It turns out our brains have a lot of little quirks, cognitive biases that operate largely unnoticed. These biases have long been a fascination, and when they show up in this column it's usually to explain how they can get in the way of living happier lives.

That was the theme of a talk I just gave, too, invited by the Minneapolis branding and design firm Capsule. One question from the floor got me wondering if I'd been thinking about this wrong. Can't some of these little mental shortcuts make our lives easier?

There's one called availability, for instance, which is how we calculate probability and make decisions based on what we can most easily remember. That's usually just the most recent thing that happened. We're too busy to run calculations on all the available evidence, and shortcuts help us get us through the day.

Maybe biased thinking undermined my understanding of thinking biases, but I admit that after years of reading I still have no more than a layman's understanding of any of this. But here are a few examples that support the idea that biases really seem to chip away at happiness.

One is the so-called negativity bias, the tendency people have to more strongly recall bad experiences. Like other biases, this seems to have gotten hard-wired into us over our long evolutionary past, since humans needed to remember threats to survive.

Then there's hedonic adaptation. That's how we enjoy some shiny new thing only when we first get it, like a fancy BMW automobile that soon becomes just another car that gets us to work.

But here's the sad part about that car. If a person is forced to sell the BMW and go back to driving a 20-year-old Ford Escort, that'll make him miserable. The mental quirk working here is called loss aversion.

So a fancy car doesn't make someone happy very long but losing it might make them unhappy forever.

It seems like loss aversion would've been useful to our way-back ancestors, too. Families headed by people carelessly indifferent to the disappearance of all the stored up food probably died out eons before they could help fill our gene pool.

If I had to pick one bias that most bugs me it's got to be self-serving bias, popping up occasionally in writing on personal finance. In a nutshell, it's the tendency to give ourselves all the credit for the good things we have in our lives, while the bad stuff we blame on external factors.

This helps produce people who are awfully smug about their $5 million net worth when there are plenty of equally hardworking Americans who would be thrilled if they could someday get their savings account balance up to $5,000.

Even worse, once they've gotten used to thinking that they deserved every nickel of the $5 million, it seems easy to think they really deserve $10 million.

One of the best ways to illustrate this came from the writer Michael Lewis, author of "Moneyball," "The Big Short" and other bestsellers. He found research from the University of California Berkeley that the principal researcher later called the "Cookie Monster" study, a fun little experiment with undergraduates and some cookies.

In this case the researchers put together groups of three students to work together discussing and writing about a pressing problem. Just before the discussion started, the researchers arbitrarily picked one student to facilitate the work.

Then, a half-hour into the exercise, the researchers brought in a snack, just four cookies on a plate. Get it? Four cookies for three students.

The facilitator, picked at random just minutes before, invariably ate the extra cookie.

Berkeley Prof. Dacher Keltner concluded that even a tiny bit of power over others can turn someone selfish. But Lewis found in the Cookie Monster experiment a great story that might help a very privileged audience stop and think about their good fortune.

Here the people in the study lucked into a role they had done precisely nothing to earn and yet easily felt entitled to the extra cookie.

That's the self-serving bias whirring away in the background, and the point Lewis wanted to make. It's too easy to think we deserve all the extra cookies we've been handed.

This kind of bias looks like a chronic problem, but after being gently challenged at that recent talk I dug into the file to land on at least one upside in blatantly self-serving thinking.

It's the benefit of what's called the psychological immune system, popularized in the last 20 years or so by researchers including the Harvard University psychologist Daniel Gilbert.

Gilbert and his research colleagues had clearly been intrigued by how lousy people are at predicting how they're going to feel about something that might happen to them.

One thing they noted was far too much dread over something bad that could lie ahead, not realizing that people really are awfully resilient. They manage to crawl away from a personal disaster and in time pretty much fully recover.

One reason that can happen is the ability people seem to have to make up stories in their heads about these bad experiences where they come out looking pretty good. It's undeniably self-serving. Gilbert, though, thought of this mental quirk as a gift people need to better appreciate.

Like a lot of people, I've had a job come to an abrupt end, and some sort of self-serving bias kicked in so fast the psychological wound was mostly healed by dinner time. Of course, anyone listening in on the muttering during the drive home would have heard a grown-up sounding like a 9-year-old.

"Fine. I was sick of working for your stupid firm anyway."

lee.schafer@startribune.com • 612-673-4302