Cooking: Digestion & Energy Uptake (3rd article is out)

Oh hey- I’ve been so busy with my dissertation defense, I didn’t even notice my third encyclopedia chapter coming out- Cooking: Increased Energy/Reduced Digestion ūüėÄ If you can’t open the full text on the website, the¬†PDF file is also¬†HERE.

Short intro: Cooking food is a unique human activity spanning across all cultures, and humans appear to be evolutionarily adapted to this crucial aspect of their diet (Wrangham and Conklin-Brittain 2003). The value of cooking lies in its ability to widen the range of foods that are safe to eat (whether by making their digestion easier or neutralizing toxic compounds) as well as extract more energy from the foods ingested. Both human and animal studies illustrate that the more cooked food there is in a diet, the greater the net energy gain for the eater (Carmody and Wrangham 2009), and a diet of raw foods is energetically inadequate even when various nonthermal processing methods are employed (Koebnick et al. 1999). The effect of cooking on the energy gain from eating includes several mechanisms: increasing digestibility and thus caloric value of ingested foods, lowering the body’s energetic costs of digesting, and mounting an immune defense against food pathogens.

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First encyclopedia chapter published!

Woohoo!

My first encyclopedia chapter is finally published!

I was researching and writing this one¬†while traveling across 3 countries this summer and collecting data, so the whole process was not necessarily a piece of cake. Thus, i’m extra pumped¬†this is finally¬†available! If you want to read the chapter but can’t access it, feel free to email me and i’ll send you the PDF ūüôā -> mvoytyuk (at) asu.edu

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NOTE: It’s actually highly ironic for me to write on how cooking could have been instrumental in the evolution of our large brains-¬†I spent 2 years as a highly motivated raw vegan! Indeed, I took several “raw cooking” and educational courses in different parts of the U.S. (Illinois, California), was a private raw “chef”, and taught raw veganism workshops for over a year at a food co-op I managed.

This chapter doesn’t actually¬†comment on whether there could be health benefits to eating a diet higher in uncooked foods. It does focus on highlighting the fact that we appear to be particularly adapted to cooking. So, I’d say it does¬†not support a 100% raw vegan diet as a worthy endeavor.

Click HERE for the encyclopedia page, and here is the short intro:

The disproportionately big human brain is a conundrum ‚Äď it is larger than would be expected for a primate of our size, and it is a very energetically expensive organ. Since human basal metabolic rate (BMR) is not elevated to match such a big brain, the extra energy needed to sustain it suggests a dietary explanation. Feeding the large brain would likely require a shift to a high-quality diet: one comprised of energy-rich, easily digestible foods. This hypothesis is supported by a number of anatomical features: smaller teeth, jaws, stomachs, and a shorter large intestine. Two key elements of human subsistence ‚Äď cooking and meat eating ‚Äď have been proposed as a possible means of achieving this high-quality diet.

Evil Genius’ playlist: instrumentals and rock&roll

Well, this short post will be off my usual topics.

My husband¬†& I have just been (once again) discussing how villains in various forms of media are often shown enjoying classical music (my husband is an orchestral conductor, thus the topic) . We’re suspecting it has to do with trying to portray their higher intelligence. But why do we think super intelligent people are into “classical music”?

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Want to be an evil genius? Both routes work! (yes I might be using¬†my husband’s photo in this illustration, mkay? My husband is on the bottom RIGHT- just to be clear)

First of all, a bit of interesting information that particularly pleases the rock fan in me:¬†¬†“more intelligent”* individuals prefer reflective and complex genres of music (classical, jazz, blues, and folk), but they also prefer ‚Äúintensive and rebellious‚ÄĚ music (alternative, rock, and heavy metal) (Rentfrow & Gosling, 2003). I will keep putting “intelligence” in brackets because measuring such a complicated construct.. well, i’ll keep taking it with a grain of salt.

I was in a mood to procrastinate on my own work, so i began looking up studies on music and intelligence. I quickly noticed this one- since I love evolutionary perspective on all the things, I was immediately biased to read further!

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These guys propose an alternative hypothesis to the more intuitive suggestion that classical music is more complex thus highly intelligent people enjoy it more. This explanation is one I myself assumed- classical orchestral pieces are definitely more complex in their design than a modern 3-minute pop song containing up to 4 chords. In this study, Kanazawa & Perina apply the Savanna-IQ Interaction Hypothesis hypothesis (Kanazawa, 2010), which suggests that more intelligent individuals have less difficulty with evolutionarily novel stimuli- such as classical music.

…people of “higher intelligence” might find it easier to like classical music because such music is more evolutionarily novel,¬†not because it is more complex

The Savanna-IQ interaction hypothesis is a logical union of two theories: 1) evolutionary psychology argues that human brains (like any other organ of any other species) are adapted to the conditions of the “ancestral environment”, not necessarily the current one. As a result, they might find it difficult to comprehend and deal with situations that did not exist in the past; and¬†2) evolutionary psychological theory of the evolution of general intelligence¬†posits¬†that “general intelligence may have evolved as a domain-specific adaptation to solve evolutionarily novel problems, for which there are no predesigned psychological adaptations”.

Bringing that back to music: people of “higher intelligence” might find it easier to like (thus have higher preference for) classical music because such music is more evolutionarily NOVEL, not because it is more complex (music, in its evolutionary origin, is considered vocal by a recent theory- see Mithen, 2005). So the “novelty” of such music is driven by it being instrumental (evolutionarily unfamiliar) and not vocal (evolutionarily old). To summarize, the prediction is: more intelligent individuals today are more likely to appreciate purely instrumental music than less intelligent individuals because such music is evolutionarily novel, while general intelligence has no effect on the appreciation of vocal music”.

The authors test this theory in US and Britain. They measure music preference, intelligence*, and some control variables (e.g.¬†social class and education). I was of course particularly interested in how “intelligence” is measured: this study¬†used a verbal intelligence test that asks people to select a synonym for a word out of five candidates (verbal intelligence is highly correlated with general intelligence). As for music preference, respondents had to rate liking for¬†different¬†types of music, which researchers categorized as mostly vocal (15 genres) or mostly instrumental (3 genres) in the analysis. Their results in both cultural groups show that individuals who score higher on the “intelligence” test indeed are more likely to prefer :purely or largely instrumental music, while measured intelligence has no effect on preferring purely or largely vocal music. Social class and education also predict liking for instrumental music, but they do not confound the statistically significant effect of intelligence (they don’t explain it away).

This is interesting.. an immediate alternative view is that people want to “show off” their intelligence by publicly expressing a taste for instrumental music (like classical and jazz), but it’s still not clear why such genre of music came to be associated with higher intelligence in the first place. Perhaps the Savanna-IQ Interaction Hypothesis can explain why such an association developed and, once this association is popularly known, it’s easy to explain people’s motivation to cultivate this preference (to “signal” intelligence). Lastly, it’s important to¬†clarify¬†that this hypothesis does NOT propose that preferring evolutionarily novel values and preferences is MORE ADAPTIVE in the current environment- it doesn’t¬†increase reproductive success in any way.

My “research” on an off-topic took me less than an hour. This is obviously not my area of expertise so if you have any comments- please feel free to share!

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Kanazawa, S., & Perina, K. (2012). Why more intelligent individuals like classical music. Journal of Behavioral Decision Making, 25(3), 264-275.

Mithen, S. (2005). The singing Neanderthals: The origins of music, language, mind and body. London: Weidenfeld & Nicholson.

Rentfrow, P. J., & Gosling, S. D. (2003). The do re mi’s of everyday life: The structure and personality correlates of music preference. Journal of Personality and Social Psychology, 84,1236‚Äď1256.