The Spacing Effect

The "spacing effect" is a simple technique to better retain information - and perform better on exams.

1. Learn the subject
2. Take a good chunk of time (e.g. couple days) to do other activities
3. Come back and attempt to retain the subject

While retaining is difficult because of the gap, it is precisely because of the difficulty long term memory improves. Note: If the interval between learning and retaining is too short or too long, there is no spacing effect.

As an example, an experiment found that an Ontario school 5th grade students remembered far more vocabulary words they learned in 2 sessions spaced 1 week apart vs. 1 lesson.

Sweet Tooth = Sweet Nature

Research finds that people who liked sweet tastes more than savory tastes tended to be kinder. College students answered a survey about their character and also ranked food preferences. Students with a sweet tooth were more likely to volunteer.

Chivalry Boosts Cricket Mating Chances

Research finds that upon seeing a threat, a male field cricket lets his mate enter their burrow first. While males fought with males, protection - not domination - helps foster long term relations with females.

Teaching Helps Writing

Research finds that science grad students who did research and taught improved their written research proposals over 1 academic year more than those who just researched. Differences in written quality "could not account for the results, because only specific skills among those analyzed showed improvement as a function of the teaching experience."

Teeth Help with Cooking History

Researchers infer that mankind discovered cooking ~1.9 million years ago - based on studies of our molar teeth.

Most large animals chew extensively so its easy to swallow. Cooking softens the food and dramatically reduces eating time to about 5% of the day (compared to ~48% if we didn't). Softer food due to cooking helped us evolve smaller molars and smaller jaws - a little less than 2 million years ago.

Exercise Increases Productivity

Research finds that employees who exercised during work were more productive than those who relaxed or worked during those hours.

Group 1 exercised 2.5 hours/week, Group 2 relaxed during those 2.5 hours while Group 3 worked through those 2.5 hours. Not only did productivity increase over 6 months and 1 year, but Group 1 employees also lost less time to sick days.

More Roads = Better Health

Research finds that after 5 years of construction, villages near a road in northern Ecuador had a larger rise in antibiotic resistance than more remote areas. Rise in resistance to ampicillin and sulphamethoxazole nearly double that in more remote areas. The road may ease resistant microbes to migrate from person to person.

Cobra Venom Coagulates Blood

Cobra venom coagulates blood - and here's the video to prove it.

The good news - this means venom can serve as a potential foundation for stopping massive bleeding following an accident.

Want Tips? Wear Red

Analysis of 700+ French restaurant customers finds that men are tip more to women wearing red. Color, however, did not affect female patrons. The same result occurred from waitresses wearing red lipstick. In another study, women photographed against a red background were rated as more attractive by men, but not by other women. Men even sat closer to a woman in a red shirt vs. a blue one.

The Science Behind Usain's Magic

How does Usain Bolt run so fast?

Bolt is basically an abberation - when you're that big, you shouldn't be able to run that fast because muscle speed is generally related to size (e.g. squirrels move faster than giraffes). Sprinters are usually short and have more fast-twitch muscle fibers so they accelerate quicker but can't run longer distances. 800m runners are usually taller but with less fast-twitch muscle fibers. Bolt, however, is tall and has the fast-twitch fibers.

Physiologist Peter Weyand divides each cycle of a runner’s leg into what happens 1) when their foot is in the air, and 2) when it’s on the ground.

• (1) is shockingly irrelevant - at top speed, every runner (even grandpa) takes ~.3 seconds to pick their foot up and put it down again.
• (2) For most, the amount of force applied when on the ground determines speed. Calf muscles, and then hip muscles, are the prime determiners for creating this force. For this, runners can either exert the same force over a longer period (e.g. like a cheetah) or hit the ground harder. Great sprinters hit the ground with a force ~2.5 times their body weight (vs. ~2 for average people). Usain Bolt, weighing 210 lbs, creates 990 lbs of force - 4.7 times his weight.

What is the limit of human speed?

1. Non-physiological factors: being quicker off the block, running with a stronger tailwind, running at higher altitudes where thinner air exerts less drag
2. Mathematician Reza Noubary calculated, “the ultimate time for [the] 100 meter dash is 9.44 seconds.”
3. Weyand, however, say its not predictable - especially with gene therapy avenues out there.