Over the years, I’ve discovered a host of psychology experiments that are fascinating and revealing studies on human behaviour. I thought I’d talk about twelve key ones in this article. It’s not a comprehensive list, for sure, of important psychology experiments but it is a good list. The list starts out fun and harmless and becomes darker as it progresses, so you can stop at any point if you become too saddened by human nature.

I haven’t included, in this list, psychology experiments showing ‘psi’ effects, such as work done by Daryl Bem, Robert Jahn and others; I think they’re better off being place in their own list. I also haven’t included experiments about cognitive bias, although there are lots of interesting ones for that subject (e.g. anchoring bias, halo effect, priming, framing etc).

1) The McGurk Effect – Alteration of reality to fit expectations

This is so cool! It is also a revealing demonstration of how our brains shape reality to fit our expectations, to the point where we don’t even know that our brain is altering what we see and hear; a sobering reminder.

2) Count the basketball passes – Selective Attention

If you haven’t encountered this video before, it’s great fun. If you have encountered it before, it’s still a great example of our very selective attention.

3) Giving directions and a door – Change Blindness

Some psychology experiments are simply hard to believe. How can people be so unaware of changes to the world around them? In fact, we’re terrible at spotting changes. Another psychology experiment, similar to this one, had a person at a desk crouching down behind the desk to retrieve a form for a visitor, then a different person stood up with the form. In half the cases, the visitor in front of the desk did not notice any change.

4) The marshmallow experiment – Short-term vs Long-term rewards

Are you are a ‘one marshmallow’ person or a ‘two marshmallow’ person? This experiment focusses on young children but its central issue of being able to wait for a promised, larger reward, is just as relevant to adults. In other words, ‘one marshmallow’ adults smoke, drink and eat unhealthily because they are gaining immediate pleasure while ignoring the long-term negative effects of their actions (which, in the marshmallow case, is not getting a second marshmallow). ‘One marshmallow’ adults also make little effort with sorting out a pension, amassing savings, etc. Are ‘one marshmallow’ people stupid and selfish? Are ‘two marshmallow’ people boring, smug do-gooders? This choice of behaviour resonates throughout our society in many, many ways.

5) Was the experiment boring? – Cognitive Dissonance

In this experiment, the subjects are agreeing to lie to another person about how interesting an experiment is to do. The ones that agree to lie for a large fee are comfortable saying afterwards that the experiment was boring, since they were handsomely paid. The ones that agreed to lie for a small fee are uncomfortable admitting that they lied for a small fee, so they compensate for this by insisting that the experiment wasn’t boring at all, even though it clearly was dull as dishwater. They shape their spoken beliefs to fit with the choices they’ve made, even though they actually know different. Such cognitive dissonance fits strongly with Orwell’s ‘Doublethink’ and many more aspects of our belief systems.

6) Lost in the Mall – Implanting false memories

This experiment touches upon the dark world of brainwashing and mind control, an area made infamous by the CIA’s MKULTRA, ARTICHOKE and other clandestine programmes. It shows that a sizeable proportion of us are very susceptible to the manipulation of others, even to the point of us believing in a new set of entirely false memories.

7) Libet’s experiment – Issues of free will

This is a hugely influential experiment. It seems to show that our decision to do something is not actually the start of activity in our brain, indicating that our brain decided, unconsciously, to do the act before we consciously thought we’d decided. Many people have used this experiment to declare that we have no free will but, as I explained in my book, how science shows that almost everything important we’ve been told is wrong, Libet’s experiment may not mean we have no free will. Instead, it may indicate that our mind’s control over our brain is not comprehensive. Instead of possessing absolute control, we are able to train our brain over time to behave in better ways. We can also inhibit our brain’s actions if we put in enough effort. A football manager is a good analogy for such a process. A manager can’t move his players around like puppets on the football field but he can train them over time so that they work together far better than before. Our mind and our brain, I think, have a similar relationship when it comes to influence and control.

8) Candid Camera and an elevator – Desire to Conform

This one’s great fun to watch but also a dark demonstration of conformity. The subjects concerned don’t even attempt to ask why everyone else is behaving so oddly; they just go along with it. Such supine conformity is seen again, in a darker situation, in several of the later experiments in this list.

9) Asch Conformity Experiment – Willingness to be the lone voice of disagreement

There’s more supine conformity in this experiment too. There’s no coercion going on, just an unwillingness by the subject to openly disagree with everyone else in the room. I’ve personally been in this situation – a lone voice of dissent – more than once. One time was about alcohol generally, another was about the crap nature of stag weekends abroad and the third time centred around Macs vs PCs. Interestingly, in all cases, I simply took a lone stand and stated key facts but the response was toxic every time (and yes, I know, how can people get so toxic about Macs vs PCs?). Hey ho. The importance thing is whether or not one does take a stand. What sort of person do you want to be, a meek but safe sheep or an independent but bashed goat?

10) The Bystander Effect – Diffusion of responsibility

This experiment shows that Good Samaritans are not guaranteed, unfortunately. It mirrors another psychology experiment where students walked past a seemingly injured man without any of them offering to help him in his plight. The psychologists who set up that study found that the key factor that made people more helpful and aware was not their stated moral beliefs (this seemed to make little difference) but whether or not they were in a hurry. The experimenters found that the students in their experiment who had lots of time between lectures were much more likely to help the injured man. But, if the students were in a hurry, few of them helped. We now have a high-speed modern society in which ‘loafing around’ is considered a form of failure that only ‘losers’ do. We are therefore running the terrible danger of becoming a society bereft of compassion.

11) Milgram’s ’37’ Experiment – Obedience to authority

This experiment has been hugely influential. It famously shows that most people, when given instruction by an authority figure, will carry them out even to the point of killing another innocent person. Not surprisingly, the experiment is still controversial. Many people refuse to believe its conclusions, including many psychologists. There have been attempts to explain it away so that people don’t look so bad but unfortunately this is a flawed attitude, which itself indicates cognitive dissonance. As I explained in a blog post a while ago, Milgram’s experiment was replicated in the form of a fake French game show in the 1980’s called ‘game of death’. The appalling behaviour of people on the fake show clearly affirmed the dark truth of Milgram’s famous test.

12) The Stanford Prison Experiment – Loss of morality when in power

This is probably the most infamous psychology experiment of all, in terms of what it tells us about human nature. Just as with Milgram’s ’37’ experiment, many people still refuse to accept what the Stanford Prison Experiment tells us about human nature but as the documentary points out, we are reminded of its truth on a regular basis, whether through the Abu Ghraib scandal or revelations about conditions in prisons, children’s homes, nursing homes, labour camps or anywhere where one group has all the power and another group has no power.


Compiling this list has made me think again, unsurprisingly, about us human beings. What do these psychology experiments tell us about ourselves? Unfortunately, it seems to shows that we are mostly a slavish drone species, one that obeys, whatever the orders. More than half of us seem to be weak puppets, able to switch to being cruel and callous individuals given the appropriate circumstances. Such a revelation left me deeply depressed when I learned of these experiments, decades ago; I don’t think I’ve ever truly recovered from the shock. Fortunately, since then, I’ve also found out some wonderful people do stand up and defy negative orders. I think that gives us all hope.

I personally think we will develop and improve as a species in the future. We will become people who do mostly stand up and defy negative orders. We will become a race of people who will stop situations arising where tyrants can issue their toxic commands. I don’t know how long this will take but I do believe it will eventually happen. I admit that such a belief may also be a cognitive bias, but at least it’s a positive one. Here’s to the future! 🙂