You Can Invest Smarter Than a Chimpanzee

With frozen fruit-juice sticks and PVC pipes filled with peanut butter, science has identified exactly how college students are like chimpanzees.

We can thank Sarah Brosnan for this conclusion.

Brosnan, a primatologist, offered juice sticks and peanut butter to 33 chimps... 19 of whom (58%) reached for the peanut butter, while the remaining 14 (42%) selected the juice.

So when the chimps could choose between two snack offerings, it was nearly a coin flip.

Next, Brosnan and her fellow researchers gave the chimps either juice or peanut butter... then gave them a chance to trade.

Their preferences changed in a hurry.

When the chimps got juice first, suddenly only 42% were willing to exchange it for peanut butter – the exact opposite of the group's original preference.

And just 21% were willing to trade their peanut butter for juice, half of the 42% who'd previously preferred juice.

When the researchers offered a choice between peanut butter and juice, Brosnan described the chimps' selection as their preference. When the chimps received one of the snacks up front, she called it an endowment.

You can see the results of this 2007 experiment below...

Rationally, the chimps' decisions between juice and peanut butter should have been the same regardless of which food item they got first. Any chimp who'd have picked peanut butter should have jumped at the chance to exchange juice for it, and vice versa.

That's the point of the experiment... It proved that chimpanzees act irrationally.

The idea is that possession factors into a chimp's decision. When they were given a specific food item first, they were more likely to keep it than to swap it out for the other – regardless of preference.

Brosnan modeled her experiment with chimps after a famous study that had taken place some 20 years earlier...

The earlier study asked college students to complete a questionnaire, then offered three types of compensation.

The first group was offered a choice between a coffee mug and a chocolate bar. The second group got the mug, while the third group got the chocolate.

In the first group, 56% of the students chose the mug while the other 44% picked the chocolate bar. The group showed no overwhelming preference between the two rewards.

But then the researchers asked the students in the second and third groups if they'd like to trade, and the results were quite different.

In the second group, 89% of the students held on to their coffee mugs, while 90% of the third group wanted to keep their chocolate.

Sound familiar?

As Brosnan told the website Live Science...

It is really exciting to see a behavior that has often been considered irrational in humans is also present in chimpanzees. This helps us put the evolution of human behavior in perspective and may help us to understand why such behaviors would have evolved in the first place.

Brosnan also tested this phenomenon with her chimps using different types of dog toys – but without the same irrationality. She concluded that the chimps' brains reacted differently to toys than food...

Giving up something that could help with survival or reproduction may have been so risky that it wasn't worth doing even if there was the potential for something better.

Overall, this experiment was groundbreaking for behavioral science.

With respect to anyone's personal beliefs, ample evidence proves that humans and chimpanzees share a common ancestor. And the irrational behavior known as the "endowment effect" can now be traced back millions and millions of years.

Today, the endowment effect is hardwired in our brains. We all gravitate irrationally toward things we already own. And that leads us to a lot of mistakes... that can be easily avoided.

The endowment effect occurs when we place a higher value on something for no better reason than because we own it.

The college students couldn't bear to give up their coffee mugs or chocolate bars. The chimpanzees were reluctant to give up the food item they had in their hands. Whether they would have chosen the other option before no longer mattered.

Over many decades, countless experiments have proved that once something becomes "yours," it becomes a lot more valuable to you. We demand unreasonably high prices to give away the things we own.

But if your money is tied up in investments that aren't worth it, you'll miss out on ways to continue growing your nest egg.

And there's one corner of the market you're probably missing out on today...

It involves an investing technique that a longtime subscriber used to help solve his financial problems. He was able to retire at 52... send his four kids to elite colleges and graduate schools... and even help buy his elderly parents a beautiful retirement condo overlooking the Atlantic Ocean in South Florida.

Don't let the endowment effect keep you from making more money like this subscriber did. To hear his incredible story, click here.

Now, let's get into this week's Q&A... As always, keep sending your comments, questions, and topic suggestions to feedback@healthandwealthbulletin.com. My team and I read every e-mail.

Q: Hey Doc, any tips for getting sleep when I'm sick? My whole family has had the flu and it feels so much worse at night making it tough to sleep. – G.C.

A: Thanks for your question, G.C. The reason you often feel sickest at night is because of your hormones...

Your body has an internal clock that regulates the production and release of certain hormones throughout a 24-hour period. It's known as the circadian rhythm, and it synchronizes your body with the cycles of light and darkness in the environment.

During the day, your body produces varying amounts of the "stress hormone" cortisol, which helps your body perform a number of functions... like converting fats, proteins, and carbohydrates into energy... and suppressing your immune system while you're tackling the day.

Typically, cortisol levels are highest in the morning, fall gradually as the day goes on, and are very low by bedtime.

That's when levels of your "sleep hormone" melatonin rise. Melatonin allows your immune system to get to work on detecting infections in your body and releasing white blood cells to fight against them.

So if you're sick, this hormone is the reason you start feeling all the symptoms... like fever, congestion, and chills, for example.

When you know what's coming at night, you can prepare. I recommend the following to reduce the discomfort of these nightly symptoms...

• Get at least 1,000 milligrams of vitamin C every day during stretches of cold weather. This vitamin dosage will help with things like boosting your immune system's ability to kill bacteria and destroying infected or damaged cells. And while longtime subscribers know that most dietary supplements are useless or dangerous, tablets and powders are a legitimate, convenient source of vitamin C.
• Use a neti pot and take a steamy shower at night so that you'll go to bed with less congestion. Break up congestion even further by sipping some hot tea or soup. (If you use a neti pot, follow the instructions carefully and only use sterilized or distilled water.)
• Adjust your sleeping position to reduce the pressure in your head from accumulating congestion.

We hope you and your family can use these tips to feel better soon.

What We're Reading...

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Here's to our health, wealth, and a great retirement,

Dr. David Eifrig and the Health & Wealth Bulletin Research Team
February 7, 2025