Think like a scientist: check your sources

In scientific papers we are very strict about citing sources. Not only do we put a list of our references at the end of papers, but we also indicate which reference gave us which fact right there in the text: “junco fledglings have big fuzzy eyebrows (LaBarbera 2012).” This makes fact checking easy.

Scientists writing for the general public don’t usually do this. Depending on the form of a science-for-a-general-audience column, references may all be at the end only, or they may not be there at all. When researchers write about their own research without any citations, saying “My research shows…” and “Many studies have found…” but not actually citing them, it’s up to you to either blindly believe them (don’t do this) or to check their sources yourself. If they do good research, this shouldn’t be hard.

Sometimes a "research" column is like a coot: fine at first glance, but when you look close, really creepy feet. You followed that analogy, right?

Sometimes a “research” column is like a coot: fine at first glance, but when you look close, really weird feet.
You know what I mean.

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Think like a scientist: human-driven selection

A salmonella outbreak on chicken has hospitalized over a hundred people so far. Salmonella is on a lot of chicken; if you cook chicken at all regularly, you have definitely purchased and handled salmonella-tainted chicken. But that’s okay, because you cook it, and the bacteria die from the heat, and then the chicken does not kill you. No worries!

This chicken might want to kill you... Photo by Ido Mor

This chicken might want to kill you…
Photo by Ido Mor

Except that those 100+ sick people probably weren’t eating chicken sushi. Even if they did all manage to undercook their chicken, there’s this: a Costco found salmonella on its rotisserie chicken after they were cooked at 180 Fahrenheit. Chicken is “safe” when it’s cooked at 165 Fahrenheit, so 180 should be extra safe. Now, I’m not a salmonella investigator; maybe Costco lied about its cooking temperature, or maybe someone handled raw chicken and then the rotisserie chicken and that’s how they got contaminated. But there is a third option: maybe a strain of salmonella has evolved, under selection driven by you and me and everyone else who cooks their chicken, to survive cooking.

We all know what natural selection can do, how the pressure of competing with other individuals and evading predators and finding food and staying the right temperature so that you can make the most babies can drive the evolution of “forms most beautiful and most wonderful” (Darwin).

A form beautiful and wonderful: male greater kudu in Kenya.

A form beautiful and wonderful: male greater kudu in Kenya.

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Think like a scientist: levels of analysis

Today’s discussion question is: why do the lovebirds Sam and Jesse spend a lot of time together?

Jesse and Sam pause in their destruction of a picture frame to wonder what business it is of yours how they spend their time.

Jesse and Sam pause in their destruction of a picture frame to wonder what business it is of yours how they spend their time.

“Well,” someone says, “it’s because lovebirds’ brain reward centers are stimulated when they interact with their mate. Happy molecules trigger happy receptors, and the birds get happy. So they seek out that reward.”

“No,” someone else says, “it’s because a lovebird that interacts with its mate more has a stronger pair bond, making it less likely to be cuckolded. Lovebirds who spend more time with their mates have more chicks and so pass more genes on to the next generation.”

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Think like a scientist: clever Hans

Clever Hans was a horse. He lived in the early 1900s, had an article written about him in the New York Times (“Berlin’s Wonderful Horse: He Can Do Almost Everything but Talk“), and has a scientific phenomenon named after him: the Clever Hans Effect.

Why was Hans clever? He could do math – even fractions! He could tell time! He could use a calendar! He could recognize currency! He could tell the difference between musical tones! He could identify people from photographs! He could not only understand German but read and spell it! Basically, clever Hans was smarter than your Honor Roll student. And he was a horse.

That seems plausible, right?

Right?

Extremely historically accurate depiction of clever Hans doing math

Many animals are highly intelligent. For example, I have no doubt that psychologist Irene Pepperberg’s late, great African Grey Parrot Alex could have performed most of clever Hans’ tasks. But, sad to say, clever Hans was a fraud.

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Think like a scientist: correlation

Correlation does not equal causation. Done!

Just kidding. It isn’t enough simply to state that classic phrase because in the real world, we’re often still stuck with using correlations. If you want to know how lifelong exercise habits affect lifespan, you can’t take two groups of people and force one group to exercise and the other not to (“GET BACK IN THAT CHAIR! That is TOO MUCH walking to the corner store for one day!”), while keeping everything else exactly the same between the groups (“I don’t care if you’re not hungry, everyone eats one cupcake on Tuesdays!”), for their entire lives. Even if you didn’t mind knowing that you, too, would be dead before the study was over, it would be completely unethical. Instead, you study people’s natural exercise habits, and try to correlate them with lifespan. Continue reading

Think like a scientist: sample size

Science is not just for scientists. The methods of thought that underlie science are useful in all sorts of everyday contexts. Most obviously, everyone needs to be able to think like a scientist in order to interpret scientific results—you know, those newspaper headlines like “PAPER CLIP USE MAY LOWER IQ IN PREGNANT WOMEN!!” In that spirit, I’m going to write about some key concepts for thinking like a scientist. Today: sample size.

Pop quiz! You read this (totally made up) report: “Two groups of ten age- and health-matched men were monitored for heart disease. One group was given pet ferrets, while the other was not. The ferret-owning men were 8% less likely to develop heart disease over a five year period.” So: is it time to run out and get a ferret for the sake of your heart health?

You should get a ferret regardless, because ferrets are wonderful. This is my awesome old ferret Zap.

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