Tag Archives: being and seeming

Food calories are not directly related to obesity

It seems that the change in bodyweight should be a strictly increasing function of calories eaten minus calories spent. The first caveat to this claim is that calories in the food eaten do not equal the calories absorbed, which is what matters for weight gain. People differ in the efficiency of their digestion – that is what bariatric surgery relies on. Also, food labels use calories measured by the burn method (dry the food, burn it, measure the heat output), which ignores for example that coarsely chewed food chunks pass through the digestive tract relatively unchanged, thus contribute few nutrients to the organism. An extreme example is wholegrain flax (linseeds) that remain undigested due to a waxy coating. In nature, seed dispersal by birds relies on the indigestibility of the seeds.

Even if calories absorbed could be accurately measured, the type of food eaten would still matter for weight gain due to imperfect willpower. Some foods are more addictive than others, notably those rich in refined carbohydrates – an easy example is drinks that are essentially sugar-water. Consuming a given amount of calories from high-glycaemic-load sucrose makes people eat more sooner on average than ingesting the same calories from slowly digested whole grains or unsaturated fat. Similarly, ignoring willpower limitations is why abstinence-based programs to prevent sexually transmitted infections, which naively might be expected to be 100% effective, are in fact ineffective (Underhill et al 2007, doi:10.1136/bmj.39245.446586.BE).

There are various tricks to circumvent limited willpower to win the game against one’s future tempted self. To reduce temptation, food should be out of sight outside mealtimes (in cupboards, drawers, fridge) and unhealthy snacks should not be bought at all. Even seeing dishes and cutlery may trigger cravings, in which case these too should be placed out of sight when not in use.

Avoiding grocery shopping while hungry is an old piece of advice, which may be taken further by having someone else buy your food. Two people can even agree to grocery-shop for each other according to shopping lists exchanged beforehand. Online ordering may be a solution, but of course the merchants want customers to buy more, so advertise tempting foods with photos on their website. These ads can be blocked with some effort. A more sophisticated solution is to have one’s own user interface (front end) interact with the merchant’s website – scrape the data on inventory and prices, send commands to buy.

Seasonings may reduce the variety of diet

Animals may evolve a preference for a varied diet in order to get the many nutrients they need. A test of this on mice would be whether their preference for different grains is negatively autocorrelated, i.e. they are less likely to choose a food if they have eaten more of it recently.

Variety is perceived mainly through taste, so the mechanism via which the preference for a varied diet probably operates is that consuming a substance repeatedly makes its taste less pleasant for the next meal. Spices and other flavourings can make the same food seem different, so may interfere with variety-seeking, essentially by deceiving the taste. A test of this on mice would flavour the same grain differently and check whether this attenuates the negative autocorrelation of consumption, both when other grains are available and when not.

If seasonings reduce variety-seeking, then access to spices may lead people to consume a more monotonous diet, which may be less healthy. A test of this hypothesis is whether increased access to flavourings leads to more obesity, especially among those constrained to eat similar foods over time. The constraint may be poverty (only a few cheap foods are affordable) or physical access (living in a remote, unpopulated area).

A preference for variety explains why monotonous diets, such as Atkins, may help lose weight: eating similar food repeatedly gets boring, so the dieter eats less.

Claims that tickets are running out

Both for paid and free events, the organisers often advertise that only a few tickets or places remain. The ad sometimes explicitly tells the viewer to register or buy now. Such advertising is costly, so there should be a benefit to the organiser. If the tickets have already sold out, then the benefit is zero, or at least smaller than if the event is not fully booked. The positive benefit from advertising a sold-out event is to build reputation for the future as an organiser of popular events, similarly to real estate agents putting a „Sold” sign in front of a house on which they closed the deal.

Given that the benefit of costly advertising is smaller when no tickets remain, some sellers should decide to advertise if and only if the event has not sold out. More generally, the probability of advertising should increase in the number of tickets remaining. In this case, rational buyers should treat advertisements saying that limited spaces remain as signals of the opposite – frequent ads show a desperate seller facing low demand. If most buyers think this way, then such advertising is counterproductive, because buyers want to delay their purchases when the probability of being able to buy in the future is large enough. The option value of waiting comes from the possibility that the buyer’s preferences change – a better event may become available, or some emergency may prevent the buyer from attending. Getting a refund for a ticket already bought is at least a hassle and may even be impossible.

The widespread claims of limited space remaining suggest that these ads boost purchases. One reason may be buyer attention – ads make them notice the opportunity to buy, which some of them wish to take advantage of. However, any ads draw attention to the event, so raising awareness cannot be the reason for the specific claim that tickets are running out.

For most events, buyers do not want to coordinate with the largest possible crowd, only with their friends, so do not prefer a fully booked event to a half-full one. Thus claims that the event is almost sold out are difficult to explain by the seller trying to coordinate buyer actions.

Some irrationality of buyers or the seller seems necessary to explain messages that demand is low. Either the buyers take the claim literally instead of using Bayes’ rule to infer the opposite, or the seller advertises despite ads decreasing demand.

It is an empirical question whether the target audience of ads saying that space is running out interprets these as signalling high or low demand, and whether these messages make people delay their purchase or speed it up.

Slippery sidewalk paving

In Singapore, the streets are well planned and maintained, smooth and clean like everything else. However, the sidewalks have one illogical aspect: the pavement is smooth stone, which gets very slippery when wet. Singapore is tropical and humid, with frequent rain. When initially paving the sidewalks, it would be easy and probably cheaper to use rougher covering (asphalt for example) that would not get slippery in the rain. After the smooth pavement has been laid down, changing it is of course costly, and if the locals have adjusted to the slipperiness, then switching the sidewalk cover may not be worth it.

The University of Queensland has a similar problem with the sidewalk in front of its main building. The sidewalk is coarse, like yellow asphalt with 1 cm stones in it instead of sand. One would expect such a coarse surface to provide good grip in all conditions, but unfortunately the looks are deceiving. When that sidewalk gets wet, it becomes slippery like polished glass. Again, it would be cheaper and more practical to pave that sidewalk with asphalt.

A broader point generalising the above observations is that things should be field-tested in realistic conditions before putting them to widespread use. For example, the sidewalk stones should be walked and biked on under all local weather conditions before paving a street with them.

Perhaps the smooth stones in Singapore are meant to make street cleaning easier. Still, there are materials that do not become slippery when wet and are smooth enough for mechanised cleaning and cheap enough to use as pavement.

Shoe and clothing thickness is not optimally distributed

Shoes are typically of thinner material in the toes than around the ankle, but human toes are more cold-sensitive than ankles, because toes have a greater ratio of surface area to volume (thus greater heat loss) and are further from the core of the body, so get less warm blood supply. Similarly, pants are usually thicker on the butt (due to pockets) or the upper end in general (suit pants lined to the knee), in spite of the legs requiring more warming than the pelvic region. Suit jackets are open on the chest, but overlap on the belly, which needs less extra insulation. The same suboptimal distribution of warmth characterises various V-necked upper body clothes. Jackets are also thicker on the front than the back, despite most people’s backs being more cold-sensitive than bellies.

This impractical design can be explained for men’s jackets by the desire to improve the wearer’s looks with the visual illusion of broad shoulders created by the V-shape of the front of the jacket. I have written about this in more detail: https://sanderheinsalu.com/ajaveeb/?p=885

For other clothes and shoes, there seems to be no reason for the suboptimal distribution of thickness, which would be easy to fix in the manufacturing process. The extra layers of cloth added by pockets could be balanced by using thinner cloth to make the pocket area of the pants. The pocket pouches on jeans for example are usually of thin cloth, which is a step in the right direction. However, the surface of the pants covering the pockets is usually of the same cloth as the legs. Lining could easily be added to trouser legs to make these as thick as the upper part, compensating for the extra layer of cloth by manufacturing the trousers out of thinner material overall. Similarly, adding a layer to the back of a jacket is easy.

The only difficult part to compensate in the impractical thickness distribution of clothing is the thin chest cover (relative to belly and back) of a V-neck jacket, but this difficulty only arises from the desire to preserve the look of a V-neck. A similar visual illusion of broad shoulders could be created by painting a V-shaped pattern on the garment.

A different impractical aspect of shoe design that can be explained by fashion is the pointy toes. The tapering tips create an optical illusion that makes the feet seem longer, which does not necessarily improve the wearer’s looks. However, fashion is frequently ugly, as evidenced by the web search results to the phrase: „it’s called fashion, look it up”.

Formal clothing is a bad equilibrium of a coordination game

What clothing happens to be considered formal is an equilibrium of a coordination game: if most others think that a given clothing item is formal, then a person who wants to be seen as formally dressed is better off choosing that garment. If enough people who aim to dress formally choose certain clothing items, then those garments will be interpreted as formal. Different cultures and eras have considered different clothes formal, e.g. tights for men were formal in Europe during Napoleonic times, but are not now.

Current formal clothing is a bad equilibrium because suits and shirts are difficult to clean, labour-intensive to iron or press, and restrict movement. A better equilibrium would be to interpret as formal some garments that are comfortable, environmentally friendly, easy to care for and cheap. It is unfortunately difficult to change equilibria in a society-wide coordination game, because a majority of people would have to change their beliefs in a short time.

The reason why suits are seen as formal is historical: these were fashionable at the height of the British Empire, which was the richest and the most powerful country in the 19th century, thus a trendsetter in the first era of globalisation. British fashion was copied in North America and Europe, spreading to the colonies from there. Labour-intensive clothes were a way for Victorian nobility to signal wealth, because only the rich could afford to hire enough servants to make and care for their clothes. In many cultures, wearing impractical clothes (toga, long dress restricting leg movemen) has been a way to signal that one does not have to work. Similar signals of leisure were pale skin (because most work was outdoors), soft clean hands (because most work was manual and dirty), straight posture (because work often involved stooping). More extreme signals of leisure were physical changes that made most jobs of that era and region difficult or impossible: women’s foot-binding in East Asia, mandarins’ long fingernails in China.

Contrary to pale skin demonstrating leisure in Victorian Britain, in modern developed countries, a suntan is a signal of wealth, because most work is indoors and most trips to tropical places or simply outdoors are costly and time-consuming vacations. A similar reversal of the meaning of a signal is that a fat belly showed wealth when food was scarce, but in modern developed countries with an obesity epidemic, developing an athletic physique takes time and effort, so being fat is statistical evidence of poverty.

Signals of wealth have always invited cheaper imitations. For example, solariums provide suntanning cheaper than travel to the tropics. Slimness can be faked with liposuction, a corset or less drastically with a tailored waist and vertical stripes that are closer together or narrower at the waist area. The appearance of broad shoulders is achievable by wearing a suit jacket with padded shoulders.

One reason for why a business suit looks the way it does is to make the man wearing it appear taller, slimmer in the waist, and broader-shouldered, thus more masculine and attractive. The V-shape formed by the lapels uses the well-known visual perception error that an object at the open end of a V looks larger than an identical object at the tip of the V. The front of a suit jacket thus creates the appearance of a slim-bellied, muscular man. If the wearer’s belly allows, then a suit jacket usually also has a tailored waist, which further visually narrows the middle of the body. The vertical lines created by the tie and the creases of the pants make the wearer look taller and slimmer, which is often accentuated by vertical stripes on the suit. It is very rare to see a suit with horizontal stripes.

The visual illusion of attractiveness that a suit creates provides a extra incentive to stay in the equilibrium in which suits are considered formal clothing. To ease the transition to a new equilibrium in which the clothes perceived as formal are more practical, the new formal clothes should improve the wearer’s looks even more than a suit. This is not difficult, because many garments may have V-shaped patterns printed on the upper body, vertical stripes on the lower, have a tailored waist and shoulder pads. The patterns and cut may be designed based on psychology research to maximise the athletic appearance of the wearer. Anything achieved with a suit may be replicated and further optical enhancements added, for example printed outlines of muscles and puffed upper sleeves.

Arranging a virgin birth in a low-tech way

Warning: this Christianity- and Christmas-themed post may offend or disgust. The procedure described is unpleasant for the receiver.

Fertilisation of an egg cell requires sperm to reach it, which does not require breaking the hymen. A thin tube, such as a hollow straw or reed, can be inserted through the small opening in the hymen to pump sperm (obtained via male masturbation) into the vagina. The simplest way to pump the sperm is to suck it into the straw with one’s mouth and then blow it out. Another way is with an enema pump (bulb syringe) that can be constructed with primitive technology: a hollow leather ball glued to a reed using resin, tar or bone glue. The seams of the leather ball can be waterproofed with tar. The ball can be made to spring back into shape after squeezing, e.g. by constructing it with wire hoops or springs inside.

Successful fertilisation with the above method likely requires many attempts, because the probability of pregnancy from unprotected sex during the most fertile part of the menstrual cycle is 30%. Sexual activity causes hormonal changes in the female organism that facilitate fertilisation, which a simple reed insertion probably does not, but it may be possible to create similar hormonal changes with an erotic massage.

The above method can be used to arrange a virgin birth in a primitive society. No miracles are required, although a virgin giving birth may be marketed as miraculous.

Modern in vitro fertilisation technology of course expands the range of ways to engineer a virgin birth.

Bad popular science books

There is a class of books that is marketed as popular science, but have the profit from sales as their only goal, disregarding truth. Easily visible signs of these are titles that include clickbait keywords (sex, seduction, death, fear, apocalypse, diet), controversial or emotional topics (evolution, health, psychology theories, war, terrorism), radical statements about these topics (statements opposite to mainstream thinking, common sense or previous research), and big claims about the authors’ qualifications that are actually hollow (PhD from an obscure institution or not in the field of the book). The authors typically include a journalist (or writer, or some other professional marketer of narratives) and a person that seems to be qualified in the field of the book. Of course these signs are an imperfect signal, but their usefulness is that they are visible from the covers.
Inside such a book, the authors cherry-pick pieces of science and non-science that support the claim that the book makes, and ignore contradicting evidence, even if that evidence is present in the same research articles that the book cites as supporting it. Most pages promise that soon the book will prove the claims that are made on that page, but somehow the book never gets to the proof. It just presents more unfounded claims.
A book of this class does not define its central concepts or claims precisely, so it can flexibly interpret previous research as supporting its claims. The book does not make precise what would constitute evidence refuting its claim, but sets up “straw-man” counterarguments to its claim and refutes them (mischaracterising the actual counterarguments to make them look ridiculous).
Examples of these books that I have read to some extent before becoming exasperated by their demagoguery: Sex at dawn, Games people play.

Sugar-free, fat-free and low-salt claims

The three main ingredients of unhealthy food are sugar, salt and fat. The packaging of junk food often has claims of sugar-free, fat-free or low-salt in big colourful letters on the front. The trick is that the absence of one of the three ingredients is compensated by a larger amount of the other two, as can be checked from the nutrition information label.
Sometimes the claims on the front of the pack directly contradict the nutrition label, so are downright lies. I have seen packaging with the claim “sugar-free” on the front, with sugars listed in significant quantity on the nutrition label. There are some legal sanctions for falsifying the nutrition information label, but almost no restrictions on what can be claimed elsewhere on the pack, so any contradictions should almost always be resolved in favour of the nutrition label.
I have seen a sugar-free claim on a pack on which the ingredient list included brown sugar. This suggests the existence of a legal loophole (brown sugar not equalling sugar somehow) that the manufacturer wanted to use.
If the manufacturer does not want to outright lie, then a trick I have seen is to claim “no added sugar” or “no sugar or artificial sweeteners” on the pack, but add other sweeteners, e.g. sugarcane juice, molasses, high fructose corn syrup. Similarly, “no added salt” can be bypassed by adding salty ingredients, for example dried salted meat or bacon to a snack mix.
Another trick is to create the sugar in the food during the manufacturing process. For example, heating starch for a long time or adding the enzyme amylase breaks the starch into smaller-molecule sugars. So a manufacturer can claim “no added sweeteners” and yet produce sugars in the food by processing the starch in it.
A similar trick for salt is to add sodium and chloride in other ingredients and let them combine into NaCl in the food.

Joining together detached houses saves energy

Suburbs in many countries consist of detached houses that very close to each other – I have seen neighbours’ walls half a metre apart. Both houses could save energy by joining their adjacent walls together, which reduces heat loss in cold weather and heat entry (thus the need for air conditioning) in hot temperatures. Ideally, the joining should happen at the construction stage, but it is not difficult to do after the houses are built. Just enclose the space between the sides of two houses by extending the front and back wall and the roof of each house. It is not a load-bearing construction, it just has to keep the wind out from the space between the houses and provide some insulation to the space.
An added bonus is the creation of a covered storage area (a door to the space between houses should be created if the houses don’t already have a door on that side). A possible downside is that to get from the front of the house to the back, now one has to pass through the house or the storage area. But given the narrowness of the typical walkway between suburban detached houses, passing through the house may be the best route anyway. Also, when enclosing the walkway, a door can be made in each end to keep it open for passage.
Another downside is that windows on the side of the house now look into a covered storage area, not outside. But if the houses are so close together, then the only view from the window is the wall or window of the neighbour. After enclosing the side, this view becomes darker, but that does not seem a great loss. If it is, then energy-efficient lights can be installed in the enclosed area and kept on during waking hours, so people can admire their neighbour’s wall or window. Really, windows with such views can be replaced by a poster-size print-out of a photo of the view, because if the window looks into the neighbour’s window, then the neighbour probably keeps the curtains closed to prevent spying. And a wall through a window looks pretty similar to a photo of the wall stuck over the window.
The real reason to not join the houses is probably marketing and the desire to show off that it targets. People want to boast of owning a detached house, even if it is less than two metres from the neighbour’s. Knowing this, property developers construct such dwellings and market them as detached (“own your own house”, really owned by the mortgage issuer for 25 years). This is similar to the reason why McMansions are built, only the income of the buyers differs. Also similar are the pride and marketing that make people buy large SUVs, pickups and all-terrain vehicles for driving solely on paved roads.