Tag Archives: human-nature

Pheromones: unconscious messages

New Scientist has this interesting article on human pheromones. It’s amazing to find that we are unconsciously able to detect information and messages about each other.

A mothWhat are pheromones?
Actually, there is quite a lot of debate about that. Basically, pheromones are chemical messages emitted by animals that trigger responses in receivers.

For example a female moth will release a sex pheromone to signal that she is fertile. Male moths can detect and will react to the pheromone message.

There are many types of pheromones (see the Wikipedia article) including alarm pheromones, sex pheromones and food trail pheromones. They are actually fairly common in the animal world.

Pheromones in humans
Humans are animals so it would make sense that we would also produce and react to pheromones. They are evolutionarily useful after all.

For a variety of reasons (discussed in the article) there has been controversy about the existence of human pheromones. To me it seems pretty obvious that something is going on in humans too, and that is what the article is about.

Human examples
There are several examples of the unconscious effects of human pheromones:

  • It has been shown that women living together will gradually synchronize their menstrual cycles. Later experiments showed that the sweat of women in different stages of their menstrual cycle could affect the cycles of other women. Sounds like pheromones.
  • Brain scans have shown the ‘sex centre’ of women’s brains lighting up when they were exposed to the smell of a male sex hormone (found in men’s sweat). Interestingly the effect was only reliable when there was a man in the room.
  • Alarm pheromones can also be subconsciously detected by humans. Test subjects were able to distinguish between the sweat of people who had watched scary movies and people who had watched funny movies. This was despite not being able to consciously tell the difference.
  • In a similar experiment brain scans showed the fear centre of the brain lighting up when subjects were exposed to the sweat of first time skydivers.

Very interesting stuff. Luckily the effects seem pretty weak because it could get crazy if we learned to reliably affect people’s behavior using chemicals!

Being dirty makes you more ethical

The Economist has this article about a recent study showing that washing makes people view unethical activities as more acceptable. In other words being physically clean makes you more morally relaxed!

Judging moral strictness
The ‘moral strictness’ of the test subjects was tested by asking them to rate a series of acts on an ethical scale (from perfectly okay to very wrong). The activities being rated ranged from “taking money found in a lost wallet, via eating a family’s dead dog to avoid starvation, to using a kitten for sexual arousal.”

Experiment 1
In one experiment test subjects were given sentences to unscramble. Half were given neutral words only, and half were given words like “washed”, “clean” and “immaculate”.

Experiment 2
In the second experiment all test subjects were shown a 3 minute clip from Trainspotting to “incite feelings of disgust”. Half of the subjects were then told to wash their hands while half were not.

Results
In both experiments the test subjects who were clean (or thinking about being clean) rated activities as more morally acceptable.

My theory
If you read my post on the truth about morality (it’s long but I highly recommend it) then you will know that humans have a group of ‘moral instincts’. Five moral areas that come instinctively to almost all humans across all cultures.

One of those moral instincts is purity (avoiding being dirty). So when the test subjects were dirty or thinking about being dirty the purity moral instinct was triggered thereby heightening activity in the moral centers of the brain.

So when the other moral instincts (like fairness) were tested during the rating phase of the experiments the moral centers of the brain were already active and the subjects were morally stricter.

Confirming the broken windows effect

The Economist has this article about a study confirming the ‘broken windows effect‘ Basically the idea is that “observing disorder can have a psychological effect on people”.

The “tendency for people to behave in a particular way can be strengthened or weakened depending on what they observe others to be doing.”

This makes intuitive sense to me. I even see it with dirty dishes. If a few dishes accumulate in the sink then we are more likely to let more accumulate there. Before you know it, leaving a couple of dirty dishes in the sink has lead to a sink full of dirty dishes.

When applied to policing, the idea is that by getting on top of petty crimes like graffiti, littering police can prevent other crimes. It makes intuitive sense but had not actually been proven – until now.

Read the article for details on the experiments (which were quite clever).

The first experiment involved observing people passing through an alley. Some littering was observed when the alley was freshly painted but littering was more than doubled in the same alley when the walls were tagged with graffiti.

Another experiment showed that letting off fireworks during a time when they are prohibited increased littering substantially.

In the final experiment people were twice as likely to steal €5 from a postbox if the postbox was covered in graffiti. The same increase was even observed when the postbox was clear but there was litter around it!

Amazing.

Fertile women have more attractive voices

New Scientist has this article about a study showing that a woman’s voice becomes more attractive when she is most fertile. The researchers made recordings of women during four different phases of their menstrual cycles. The recordings were played in random order to both men and women, who consistently rated recordings made during fertile stages as more attractive. It seems that using voice alone both men and women are able to subconsciously detect fertility.

I’ve previously blogged about another experiment showing that fertile lap dancers earn more tips – this is just another example of the fact that we can subconsciously detect fertile women.

I explain the evolutionary reasoning behind these interesting effects in that article. In short, it pays women to conceal when they are fertile – so men will stick around all the time to be sure. It pays men to know when women are fertile so that they can focus energy when it counts.

People are less rational when they’re hungry

The Economist has this article about a study recently published showing that when blood sugar levels are low, people use more intuition to make decisions. You know, when you have been thinking hard about something for a while and then there is one last decision that you just can’t be bothered with? That is what the scientists were studying.

The scientists got a bunch of students to do a mentally taxing task and then gave half of them lemonade with sugar and half lemonade with another sweetener. Using a psychological trick (read about it in the article if you want) the scientists were able to show that those who had been mentally worked and not given sugar were more likely to make decisions using intuition instead of reason.

So it turns out that you really should take food into exams and that you really shouldn’t make important decisions on an empty stomach…

Price really does impact enjoyment

The Economist recently ran an interesting article on the impact of price on our perceptions of quality. It seems obvious that price would have an impact on the expectations of quality.

However, a recent paper has used brain scans to show that people really do enjoy wine more when they think it is expensive.

Experiment

  • Volunteers were asked to rate 5 wines of differing prices (from $5 to $90 a bottle)
  • What the volunteers didn’t know is that there were actually only 3 different wines – 2 of which were served twice at different prices
  • While tasting the part of the brain responsible for registering pleasant experiences was scanned

Results

  • The wines tasted twice at different prices were rated as better when served at a higher price
  • The brain scans showed that people really did enjoy a wine more when they thought it was more expensive

A follow up blindfolded experiment was done where volunteers weren’t given the prices. In that case they rated a wine tasted twice as the same both times. This shows that it is the price that substantially impacts enjoyment.

So the ideal is to have a situation where you are paying for a medium quality product but you believe it is worth a lot more. The key is making sure that you actually believe it is worth more.

Demo of colorblind vision

HowStuffWorks has this article detailing colorblindness. Quite interesting reading – but there is quite a lot of detail. Included in the article is this demo simulating how the world looks to those who suffer from colorblindness.

Click on the buttons to see what the image looks like to people with different types of colorblindness. This means that they would not notice a difference in the image when the button is pressed.

The truth about morality

This post is loosely based on the superb article by Steven Pinker: The Moral Instinct

Humans are afraid of heights. Around the world humans of all cultures have an in-built fear of heights. Have you ever wondered why people have that fear? It’s to prevent injury and death as a result of falling. Right?

If proximity to heights induces fear then people will feel an urge to get away from the heights. Humans who are afraid of heights are therefore less likely to die by falling (even if they aren’t conscious of why they fear heights). Evolution has made fearing heights part of what it is to be human. It is an instinct wired into our brains.

Pretty simple. But did you ever think that morality – our sense of right and wrong – is also an evolved instinct? It’s a little less obvious but true.

The basic moral principles
By studying people’s moral judgments around the world anthropologists have realized that there are basic moral principles which appear to be universal to almost all people and across all cultures (they are instinctive, not cultural). A list of these basic moral principles has been suggested by Jonathan Haidt:

  • Harm: Don’t harm innocent people
  • Fairness: Reciprocate favors and punish cheaters
  • Community: Loyalty, sharing, and solidarity among group members. Conforming to group norms
  • Authority: Follow authority and respect people with high status
  • Purity: Aim for cleanliness and and avoid defilement and contamination

These moral heuristics (rules-of-thumb) are instincts that have evolved for very good reasons – they helped our ancestors. Violating these principles makes people uncomfortable so in general the principles are obeyed. Pinker gives details on the evolution of the moral heuristics and he points out that the same moral principles have even been observed in monkeys (I have blogged about monkeys having a sense of fairness).

As an illustration I’ll go into more detail on the evolution of fairness and it’s associated emotions.

The evolution of morality – fairness
Humans benefit by working together in groups: we are all better off working together than any of us would be working alone. If I share my extra mammoth meat with you today when I have too much anyway, then you share with me later when I really need it. It pays both of us to work together.

However, as I have noted in the past, if people can cheat they will cheat – that complicates things.

Axelrod (and Dawkins among others) has shown that cooperation can and does evolve. Axelrod showed that evolutionary agents (for our discussion these are people) do naturally evolve toward a basic cooperative strategy (known as tit-for-tat). This strategy basically specifies:

  1. Cooperation by default. This means that you get the benefit of cooperating with other ‘friendly’ people.
  2. Punishment of cheating. Don’t let the ‘bad’ people get away with it.
  3. Forgiveness. Once the cheat has been punished try to cooperate again.

If you think about it, this kind of strategy makes excellent sense – cooperate as much as possible, but don’t tolerate cheats. Robert Trivers suggested that humans unconsciously implement a kind of tit-for-tat strategy through their moral emotions. Steven Pinker has given us the following examples:

  • Sympathy prompts a person to offer the first favor, particularly to someone in need for whom it would go the furthest.
  • Anger protects a person against cheaters who accept a favor without reciprocating, by impelling him to punish the cheat or sever the relationship.
  • Gratitude impels a beneficiary to reward those who helped him in the past.
  • Guilt prompts a cheater in danger of being found out to repair the relationship by redressing the misdeed and advertising that he will behave better in the future.

So, we can see how several emotions and the moral sense of fairness have evolved in order to help humans implement a strategy for cooperation. Evolution is brilliant!

So what?
All this is fascinating, but it also has some interesting and powerful implications:

1. There is no absolute right and wrong – it’s all in our heads
Our sense of right-and-wrong is actually just an evolved instinct. There is no universal right-and-wrong or good-and-evil. There is just the moral judgment that each person makes using their instincts.

If my moral judgment in a situation is different to yours then who is right? There is no universal morality to appeal to for an answer. We are both just letting our moral instinct make a judgment – so we are both right… If there is no universal morality then what can we use to compare moral judgments?

Humans have a pragmatic way of dealing with this: we agree on moral judgments and then expect everyone in our society to abide by those judgments. It’s a real cop-out and, as we will see below, sometimes those judgments don’t make all that much sense.

2. Our moral ‘sense’ is as fallible as other senses – moral illusions
Our moral sense is evolved just like our sense of sight. There are countless examples of optical illusions illustrating that even something as trusted as our sense of sight regularly gets things wrong. Similarly, our sense of morality can get things “wrong” quite easily.

We know that our sense of sight has got something “wrong” when we realize that what we thought we saw doesn’t match reality. As we have learned (implication 1 above) we have no similar way of judging our moral instincts. So when I say that our moral sense gets things wrong, I mean that if you think about some moral judgments rationally they don’t always make sense.

This is because morality is based on heuristics (the 5 moral principles from earlier) which don’t necessarily lead to rational and consistent judgments every time. The trolley problem (worth an entire posting itself) is an excellent example but here I will give a simpler example from Pinker.

A family’s dog is killed by a car in front of their house. They heard that dog meat was delicious, so they cut up the dog’s body, cook it and eat it for dinner.

What is so wrong with that? Seriously? It causes us to feel disgust because it hits the purity principle, but rationally there is actually nothing wrong with it. No one is harmed; the family is happy and had a cheap and delicious meal to remember their dog by. Be rational. We just feel that this is wrong but we don’t have good reasons for it. Perhaps this is a case of the purity instinct firing unnecessarily.

Disclaimer: As you will see if you read about the trolley problem, rationally examining moral judgments can make you feel very uncomfortable. I still don’t know what to think…

3. Sometimes what we perceive as immoral is just a different weighting on the basic moral principles
We now know that there is no universal moral code against which we can measure moral judgments. We also know that sometimes our moral judgments don’t even make rational sense. How can we judge others as wrong or immoral if their judgments differ from our own?

As Pinker points out, the other party is often also acting morally, he/she has just used different priorities on the 5 moral principles:

Many of the flabbergasting practices in faraway places become more intelligible when you recognize that the same moralizing impulse that Western elites channel toward violations of harm and fairness (our moral obsessions) is channeled elsewhere to violations in the other spheres. Think of the Japanese fear of nonconformity (community), the holy ablutions and dietary restrictions of Hindus and Orthodox Jews (purity), the outrage at insulting the Prophet among Muslims (authority). In the West, we believe that in business and government, fairness should trump community and try to root out nepotism and cronyism. In other parts of the world this is incomprehensible — what heartless creep would favor a perfect stranger over his own brother?

Where to from here?
In short: I don’t know.

For instance, I have previously attacked those Muslims who thought it just to execute a teacher for naming a teddy bear Muhammad. Now I realise that they were acting by their own moral judgments. I still disagree strongly with them, but I now know that I don’t have any moral high-ground.

I would like to appeal to rationality to show that I am right, but I’m not at all comfortable using rationality against all moral decisions so that would be cheating.

Knowing more about the true nature of morality hasn’t given me the answers – it has made me realise that I wasn’t even aware of the questions!