No one gets up in the morning and says, "Today I am going to make a ton of bad decisions." All of us strive to avoid dumb calls and unforced errors. We police ourselves for stupidity, laziness, and arrogance. If we're smart, we even keep an eye out for the many biases that afflict the human brain. 

Yet we still all sometimes make bad decisions. Why? 

There may be as many answers to that question as there are human frailties, but according to one VC, some causes of dumb decisions pop up more frequently than others. On the blog of his firm recently, Morgan Housel outlined some of the most common ways he sees smart people go wrong in their thinking, beyond the obvious offenders like greed and fear of failure. 

The long post is well worth a read in full but here are a handful of ideas to get you started, along with a sprinkling of research and examples to back up Housel's claims. 

1. Tribalism 

A quick look at America's polarized politics should confirm that people often make dumb decisions because of the emotional charge they get out of belonging to a particular tribe. But the problem isn't confined to politics. "Tribes are everywhere -- countries, states, parties, companies, industries, departments, investment styles, economic philosophies, religions, families, schools, majors, credentials," Housel points out.  

We love the feeling of identity and support we get from belonging to a tribe, but Housel cautions that "tribes have their own rules, beliefs, and ideas. Some of them are terrible." Members of the tribe often go along with these idiocies anyway to avoid threatening their identity. 

2. The wrong incentives 

We think our morals are internal, that we'd hold to our principles no matter the external circumstances. A boatload of research shows that's not true

"Incentives can tempt good people to push the boundaries farther than they'd ever imagine," Housel writes. "It's hard to know what you'll consider doing until someone dangles a huge reward in your face, and underestimating how adjustable the boundaries can become when rewards rise is a leading cause of terrible decisions."

3. Compounding small errors 

We're all on the alert for catastrophic errors, but that means we're often less vigilant for small mistakes. "It's hard to see how being a little bit of an occasional jerk grows into a completely poisoned work culture. Or how a handful of small lapses, none of which seem bad on their own, ruins your reputation," Housel offers as examples. 

4. Underestimating adaptation 

"History does not repeat itself, but it rhymes," Mark Twain is often (probably erroneously) quoted as saying. Whatever the provenance of the saying, it's popular because it captures a useful truth. While human nature is constant, causing similar situations and conflicts to crop up again and again, the way those conflicts play out each time is different. That's because people learn and adapt. Housel feels many of us don't pay nearly enough attention to this process. 

"Things change. People adapt and figure out better ways. Same thing in the other direction: nothing too good stays that way for long because it breeds complacency and catches competitors' attention," he reminds readers. 

5. Letting people with different values influence you

"Taking your cues and advice from people with different goals, abilities, and desires than you is an easy road to misery. But it's common, because smart people you look up to tell you it's good advice," Housel warns. Before you emulate or envy someone, consider whether that person is even playing the same game in life you are. 

6. Ignoring unknown unknowns 

When the Iraq war collapsed into disaster, Secretary of Defense Donald Rumsfeld blamed the government's failure on "unknown unknowns." Housel points out that during the Vietnam war, Secretary of Defense Robert McNamara was similarly misled by unknown unknowns and his own lack of humility in recognizing the possibility they existed. This doesn't just apply to generals and cabinet members. It applies to the rest of us too. 

7. Uncritical copying

Tim Cook gets up at 4 a.m. every day. You want to be a world-class business leader, so you should get up every day at the crack of dawn too, right? Not really, Housel says. While you assume Cook's morning routine is key to his success, his early rising may have little to do with his rise up the corporate ranks. 

"Even if you ask [people] for a road map, they might lead you down a different path than the one they took themselves," he writes. "This is especially true because people like good, clean, easy stories about cause and effect, meaning the story you get might be totally different from the complex set of circumstances that caused an outcome you're trying to copy or avoid."