Self-help books, persuasion manuals and glossy magazine articles often advise that mimicking body language can increase how much others like us. But is it really true that mimicry causes others to like us, or is mimicry just a by-product of successful social interactions?

Although it had long been suspected that copying other people's body language increases liking, the effect wasn't tested rigorously until Chartrand and Bargh (1999) carried out a series of experiments. They asked three related question:

1. Do people automatically mimic others, even strangers?
2. Does mimicry increase liking?
3. Do high-perspective-takers exhibit the chameleon effect more?

(And, fourthly, what does all this have to do with hypnotism? On which, more later.)

Do people automatically mimic others, even strangers?

The set-up: Testing what they call 'the chameleon effect', in their first study 78 participants were sat down to have a chat with an experimental insider or 'confederate' who had been told to vary their mannerisms in systematic ways. Some did more smiling, others more face touching and still others more foot waggling.

Result: Yes, participants did naturally copy the confederate (who they'd only just met) as measured by face touching, foot waggling and smiling. Face touching only went up 20%, but rate of foot waggling went up by an impressive 50% when participants were inspired by another foot waggler.

Does mimicry increase liking?

In the second experiment Chartrand and Bargh wanted to see if all this foot waggling and face touching has any actual use, or whether it is just a by-product of social interactions.

The set-up: 78 participants were sent into a room to chat with a stranger (another experimental confederate) about a photograph. With some participants the confederate mimicked their body language, with others not. Afterwards participants were asked how much they liked the confederate and rated the smoothness of the interaction, both on a scale of 1 to 9.

Result: Mimicry did indeed work to increase liking. When their body language was copied, participants gave the confederate an average mark of 6.62 for liking (and 6.76 for smoothness). When they weren't being mimicked participants gave the confederate an average of 5.91 for liking (and 6.02 for smoothness). Not a huge difference you might say, but still a measurable effect for a change in behaviour so subtle most people didn't even notice it.

Do high-perspective-takers exhibit the chameleon effect more?

Since we're all different, some people will naturally engage in mimicry more than others. But what kinds of psychological dispositions might affect this? Chartrand and Bargh looked at perspective-taking: the degree to which people naturally take others' perspectives.

The set-up: Fifty-five students filled out a perspective-taking questionnaire, along with a measure of empathy, then they were sat opposite an experimental confederate, doing the same old face rubbing and food waggling routine from before.

Results: Participants who were high in perspective-taking increased their face-rubbing by about 30% and foot waggling by about 50% compared with the low-perspective-takers. Differences between people in empathic concern, however, had no effect on mimicry suggesting it was the cognitive component of perspective-taking that was important in encouraging mimicry rather than the emotional.

Hypnosis and the chameleon effect

So the 'chameleon effect', far from being the preserve of cold-blooded reptiles, is actually a warm response facilitating social interactions. This experiment suggests most of us do it automatically to varying degrees and, just as the glossy magazine advice goes, it does encourage other people to like us.

But what's this connection between social mimicry and hypnotism that I mentioned at the top? Well, one influential theory of hypnosis says that in the hypnotic state the conscious will is weakened so that suggestions from the hypnotist are carried out automatically (Hilgard, 1965).

This is actually an extreme version of what happens when we mimic other people's body language. In some senses, when two people are really getting along, their feet-waggling and face-touching in perfect harmony, it's because they've hypnotised each other.

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How can you live a happier life? How can you discover your strengths and build on them? What is the case for hope and optimism? Dr. Robert Biswas-Diener, a happiness researcher and life coach, addresses these important questions in a workbook aimed at helping you understand and apply the lessons from the latest research in positive psychology.

The Invitation to Positive Psychology workbook (PDF, $17.95) uses an engaging style to introduce the burgeoning field of positive psychology. This workbook, presented as a six-week course with exercises and points for reflection, could help you sharpen your skills, generate new ideas, perhaps even increase revenue for your business.

Two other positive psychology workbooks are also available. Like the Invitation to Positive Psychology, a second workbook, Positive Motivation (PDF, $17.95) is aimed at a general audience and is appropriate for people from all walks of life. The third workbook, Positively Happy (PDF, $17.95) is by Dr Sonja Lyubomirsky & Dr Jaime Kurtz. This contains more advanced material aimed at educators, coaches, managers and others with an interest in motivation.

All the workbooks try to balance the scientific underpinnings of positive psychology with activities and exercises that will help readers apply these concepts in their everyday lives.

Dr. Biswas-Diener's site also has general and academic articles as well as audio and video on positive psychology which is available to download, listen and watch for free.

→ All the workbooks are available from the Intentional Happiness site.

This is a sponsored post.

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One of the most incredible things about the human mind is its resilience. Let's face it, life can be pretty depressing at times, and yet people generally push on much the same as they always have, sometimes even with a spring in their step and a smile on their face.

How come one day it seems like the world is going to end and the next there's hope? And how come our bad moods lift so unexpectedly, like a brick sprouting wings and disappearing into the clear blue sky?

The reason is that we all have a secret weapon against bad moods: a psychological immune system. When we experience events that send us into an emotional tailspin it kicks in to try and protect us from the worst of it.

The difference between our physical and psychological immune systems is that we know all about the physical. When we get a cold, we can see and feel our body's defence systems activating. Not so for the psychological immune system. Strangely we seem not to notice it working away to reduce our negative emotions, our secret weapon is also a secret from ourselves.

How bad will rejection make you feel?

Daniel T. Gilbert of Harvard University and colleagues explored this surprising phenomenon in a series of classic social psychology studies (Gilbert et al., 1998). They set up a situation almost all of us would be familiar with: going for a job interview and getting rejected.

First they led participants to believe they were going for a job interview but, beforehand, in amongst a load of other irrelevant questions, asked them how they would feel if they didn't get it. Of course there was no job to get and they were duly told they didn't get it, then asked, again subtly, how they felt now.

What Gilbert and colleagues were interested in was the difference between how people predicted they'd feel and how they actually did feel. In other words: do people understand they have a psychological immune system and that it will do its best to improve their emotional state after the rejection?

There was also a little twist in the tail: half the participants were told they were being evaluated for the job by one person and the other half that they were being evaluated by three people. This meant that for the half that were evaluated by one person it was easier to rationalise a rejection since when there's only one person deciding it's easier to imagine the decision had more to do with that person's individual preferences. Being rejected by three people, though, feels like a more considered judgement for the candidate.

Not as bad as you think

Here's what the experimenters found. People predicted that if they were rejected they would feel about 2 points worse on a scale of 1 to 10 compared with their mood when they started the experiment. Immediately after rejection those for whom the rejection was easy to rationalise only felt 0.4 of a point worse on the scale, not 2 points worse. And after 10 minutes they felt just as happy as when they started the experiment. The immune system had done its work and people's predictions were way off.

The news wasn't quite so good for the participants in the difficult to rationalise condition, but it still wasn't as bad as they expected. Instead of a 2 point drops on the scale of 1 to 10, they experienced a 0.68 drop immediately and 1.25  point drop after 10 minutes, once the rejection had really sunk in. The strain was much greater for the psychological immune system in this condition and it didn't do so well.

Still, neither groups felt as bad as they thought they would. And this pattern is repeated again and again across other psychology studies. When we're hit by one of life's frequent kicks to a tender zone, the psychological immune system starts its work, rationalising what has happened and, over time, stopping it hurting as much as we expected.

In the same paper Gilbert and colleagues report studies on people getting dumped by their partners, told their personalities are deficient and academics failing to get tenure. The pattern repeats: people think it's going to feel bad, but generally it's not as bad as they expect, and people recover quicker than they predict.

The merciful unconscious

The very fact that we don't seem to notice our psychological immune system is probably the only reason it works at all. After all, in order to feel better we have to conveniently forget some important facts, such as how much we wanted the job we didn't get, loved the partner who walked out or were enjoying the ice cream we just dropped.

But the good news is when life deals out its cruellest blows, our unconscious will be working overtime to find the upside. That's why life often doesn't turn out to feel as bad as we think. Soon enough most of us are on our merry way again with a bounce in our step, all thanks to the merciful but covert work of the psychological immune system.

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It might seem like an undemocratic question but it's one that's always plagued me: why do I bother voting? Most people know their own tick in the box is hardly worth it when weighed against the effort involved in getting registered and actually going to vote, let alone when weighed against all the other people voting.

Quattrone & Tversky (1984) had a hunch that there was another, more complex psychological reason that people vote, to go along with the usual explanations. Not only, they guessed, do people vote because of their democratic duty and their participation in a shared social ritual, but the act of voting ourselves tells us how others are going to vote.

This doesn't make much sense at first sight but the mind works in mysterious ways. People know there are others who think the same way they do and if people like them don't vote then their candidate is unlikely to win. Therefore they need to vote themselves.

It sounds like a twisted kind of logic but Quattrone & Tversky found some evidence for it in a study following on from the one they did about self-deception (see the connection?!). They found that in a simulated voting situation participants behaved as though they believed that their own vote actually caused other people to vote in the same way they did.

In other words, people seem to behave as though their own behaviour is diagnostic of other people who think the same way.

This is another neat demonstration of our powers of self-deception and one reason self-deception can work to society's advantage. Democracies generally view voting as a good thing (with some notable exceptions!) and try to encourage it, yet people rationally understand that their individual vote makes practically no difference. But when we see our vote as signalling how others will behave, it becomes much more important.

There are many other areas of our lives where seemingly insignificant actions by individuals are multiplied to produce extremely beneficial outcomes. For example when we give money to charity we may only be able to afford a small amount; rationally we understand it won't make much difference, but when this money is combined with all that given by like-minded people, the total amount becomes very worthwhile.

The same probably goes for any number of other prosocial behaviours in which we assume our own behaviour is diagnostic of others. It's one of the unexpected benefits of our penchant for self-deception: sometimes our own narcissism works to society's advantage.

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In theory the one person we should never, ever, lie to is ourselves. Surely lying to ourselves is counter-productive? Like calmly and deliberately shooting yourself in the foot or taking a hot toasting fork and plunging it into your eye?

But look around and it's not hard to spot the tell-tale symptoms of self-deception in other people. So perhaps we are also deceiving ourselves in ways we can't clearly perceive? But is that really possible and would we really believe the lies that we 'told' ourselves anyway? That's what Quattrone & Tversky (1984) explored in a classic social psychology experiment published in the Journal of Personality and Social Psychology.

Lies, damn lies and psychologists

Any study of self-deception is going to involve a fair amount of bare-faced lying, and Quattrone & Tversky's (1984) research was no different. They recruited 38 students who were told they were going to take part in a study about the "psychological and medical aspects of athletics". Not true, in fact the researchers were going to trick participants into thinking that how long they could submerge their arms in cold water was diagnostic of their health status, when really it showed just how ready people are to deceive themselves. This is how they did it.

The participants were first asked to plunge their arms into cold water for as long as they could. The water was pretty cold and people could only manage this for 30 or 40 seconds. Then participants were given some other tasks to do to make them think they really were involved in a study about athletics. They had a go on an exercise bike and were given a short lecture about life expectancy and how it related to the type of heart you have. They were told there were two types of heart:

• Type I heart: associated with poorer health, shorter life expectancy and heart disease.
• Type II heart: associated with better health, longer life expectancy and low risk of heart disease.

Half were told that people with Type II hearts (apparently the 'better' type) have increased tolerance to cold water after exercise while the other half that it decreased tolerance to cold water. Except of course this was all lies only made up to make participants think that how long they could hold their arm under water was a measure of their health, with half thinking cold-tolerance was a good sign and half thinking it was a bad sign.

Now time for the test: participants had another go at putting their arms into the cold water for as long as they could. The graph below shows the average results before and after all the blatant lying (in the name of science of course!):

As you can see the experimental manipulation had a strong effect. People who thought it was a sign of a healthy heart to hold their arms underwater for longer did just that, while those who believed the reverse all of a sudden couldn't take the cold. That's all well and good, but were these people really lying to themselves or just the experimenters and did they believe those lies?

Hook, line and sinker

After the arm-dunking each participant was asked whether they had intentionally changed the amount of time they held their arms underwater. Of the 38 participants, 29 denied it and 9 confessed, but not directly. Many of the 9 confessors claimed the water had changed temperature. It hadn't of course, this was just a way for people to justify their behaviour without directly facing their self-deception.

All the participants were then asked whether they believed they had a healthy heart or not. Of the 29 deniers, 60% believed they had the healthier type of heart. However of the confessors only 20% thought they had the healthier heart. What this suggests is that the deniers were more likely to be truly deceiving themselves and not just trying to cover up their deception. They really did think that the test was telling them they had a healthy heart. Meanwhile the confessors tried to tell a lie back to the experimenter (seems only fair!), but privately the majority acknowledged they were deceiving themselves.

This experiment is neat because it shows the different gradations of self-deception, all the way up to its purest form, in which people manage to trick themselves hook, line and sinker. At this level people think and act as though their incorrect belief is completely true, totally disregarding any incoming hints from reality.

So what this study suggests is that for many people self-deception is as easy as pie. Not only will many people happily lie to themselves if given a reason, but they will only look for evidence that confirms their comforting self-deception, and then totally believe in the lies they are telling themselves.

Explains a lot, don't you think?

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Surely one of the best ways to generate motivation in ourselves and others is by dangling rewards?

Yet psychologists have long known that rewards are overrated. The carrot, of carrot-and-stick fame, is not as effective as we've been led to believe. Rewards work under some circumstances but sometimes they backfire. Spectacularly.

Here is a story about preschool children with much to teach all ages about the strange effects that rewards have on our motivation.

It's child's play

Psychologists Mark R. Lepper and David Greene from Stanford and the University of Michigan were interested in testing what is known as the 'overjustification' hypothesis—about which, more later (Lepper et al., 1973).

Since parents so often use rewards as motivators for children they recruited fifty-one preschoolers aged between 3 and 4. All the children selected for the study were interested in drawing. It was crucial that they already liked drawing because Lepper and Greene wanted to see what effect rewards would have when children were already fond of the activity.

The children were then randomly assigned to one of the following conditions:

1. Expected reward. In this condition children were told they would get a certificate with a gold seal and ribbon if they took part.
2. Surprise reward. In this condition children would receive the same reward as above but, crucially, weren't told about it until after the drawing activity was finished.
3. No reward. Children in this condition expected no reward, and didn't receive one.

Each child was invited into a separate room to draw for 6 minutes then afterwards either given their reward or not depending on the condition. Then, over the next few days, the children were watched through one-way mirrors to see how much they would continue drawing of their own accord. The graph below shows the percentage of time they spent drawing by experimental condition:

As you can see the expected reward had decreased the amount of spontaneous interest the children took in drawing (and there was no statistically significant difference between the no reward and surprise reward group). So, those who had previously liked drawing were less motivated once they expected to be rewarded for the activity. In fact the expected reward reduced the amount of spontaneous drawing the children did by half. Not only this, but judges rated the pictures drawn by the children expecting a reward as less aesthetically pleasing.

Rewards reduce intrinsic motivation

It's not only children who display this kind of reaction to rewards, though, subsequent studies have shown a similar effect in all sorts of different populations, many of them grown-ups. In one study smokers who were rewarded for their efforts to quit did better at first but after three months fared worse than those given no rewards and no feedback (Curry et al., 1990). Indeed those given rewards even lied more about the amount they were smoking.

Reviewing 128 studies on the effects of rewards Deci et al. (1999, p. 658) concluded that:

"tangible rewards tend to have a substantially negative effect on intrinsic motivation (...) Even when tangible rewards are offered as indicators of good performance, they typically decrease intrinsic motivation for interesting activities."

Rewards have even been found to make people less creative and worse at problem-solving.

Overjustification

So, what's going on? The key to understanding these behaviours lies in the difference between intrinsic and extrinsic motivation. When we do something for its own sake, because we enjoy it or because it fills some deep-seated desire, we are intrinsically motivated. On the other hand when we do something because we receive some reward, like a certificate or money, this is extrinsic motivation.

The children were chosen in the first instance because they already liked drawing and they were already intrinsically motivated to draw. It was pleasurable, they were good at it and they got something out of it that fed their souls. Then some of them got a reward for drawing and their motivation changed.

Before they had been drawing because they enjoyed it, but now it seemed as though they were drawing for the reward. What they had been motivated to do intrinsically, they were now being given an external, extrinsic motivation for. This provided too much justification for what they were doing and so, paradoxically, afterwards they drew less.

This is the overjustification hypothesis for which Lepper and Greene were searching and although it seems like backwards thinking, it's typical of the way the mind sometimes works. We don't just work 'forwards' from our attitudes and preferences to our actions, we also work 'backwards', working out what our attitudes and preferences must be based on our current situation, feelings or actions (see also: cognitive dissonance).

When money makes play into work

Not only this but rewards are dangerous for another reason: because they remind us of obligations, of being made to do things we don't want to do. Children are given rewards for eating all their food, doing their homework or tidying their bedrooms. So rewards become associated with painful activities that we don't want to do. The same goes for grown-ups: money becomes associated with work and work can be dull, tedious and painful. So when we get paid for something we automatically assume that the task is dull, tedious and painful—even when it isn't.

This is why play can become work when we get paid. The person who previously enjoyed painting pictures, weaving baskets, playing the cello or even writing blog posts, suddenly finds the task tedious once money has become involved.

Yes, sometimes rewards do work, especially if people really don't want to do something. But when tasks are inherently interesting to us rewards can damage our motivation by undermining our natural talent for self-regulation.

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People love to believe in supernatural powers like telepathy. At least one-third of Americans report a belief in extra-sensory perception (ESP), with a further 40% refusing to rule out the possibility. Surveys in Europe reveal similar figures with one study finding that almost two-thirds of people believe in some form of ESP (further figures on the NSF website).

Psychologists are particularly interested in why people have these sorts of beliefs. One common explanation is that people's natural desire to make sense of what is a fundamentally random and confusing world is so strong that patterns are seen where there are none. It's like when we look at a visual illusion or watch a good magician: we're easily tricked.

So what kinds of situations make us more prone to this magical thinking? This is the question that inspired Fred Ayeroff and Robert P. Abelson to carry out a classic social psychology experiment on a group of students at Yale University in the 1970s (Ayeroff & Abelson, 1976). They wanted to see if a simple experimental manipulation could be used to get people to act as though they believed in telepathy.

For their experiment they used 32 participants and a fairly standard set-up for a parapsychological ESP study. One participant, the sender, was sent to a soundproof room and told to transmit a series of images telepathically. The other participant, the receiver, was sent to another soundproof room and told to get ready to receive (this was the 70s remember!).

There were two experimental manipulations:

1. Good vibe. Some receivers and senders were sat down before the telepathy started to 'practice' together. This was designed to get a 'good vibe' going between sender and receiver.
2. Control. Some senders and receivers were allowed to choose which, from a set of cards, they actually used to transmit telepathically.

Then, once the experiment got under way, both sender and receiver were asked to say how confident they were that they had successfully transmitted (or received) each card. Participants weren't told how they had done.

Mind-reading?

Looking at the results Ayeroff and Abelson found no support for telepathy. The participants had done no better than chance. But, when they looked at how confident the participants had been about their telepathic powers, they did find an interesting effect.

When participants had not been allowed to choose the cards nor allowed to speak to each other before the experiment, their confidence in their performance was absolutely accurate: they predicted they wouldn't be able to beat chance.

But, when they spoke to each other first, and when they chose the cards to transmit and receive, their confidence shot way up to almost three times that expected by chance (see graph above showing results for the 4 conditions). Suddenly participants were acting as though they had been converted into believers simply by chatting to their telepathic partner and choosing the cards.

Believers

So, no evidence of ESP, but evidence of the kinds of social situations in which people can be induced to believe in ESP. Firstly when there is a good vibe between people they are more likely to believe that ESP is possible. Secondly when wannabe telepaths have control over the situation they are more likely to believe ESP is possible.

What this experiment shows is how remarkably easy it is to (effectively) turn people into believers in telepathy. This makes it much clearer why people have a tendency to grasp at straws when trying to make sense of what is a random and chaotic world.

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It's a statistic often quoted to show how callous and heartless people are. It's the kind of number the misanthrope TV doc Gregory House (played by Brit Hugh Laurie) should have tattooed across his forehead.

But what kinds of lies are people telling? Are they covering up dastardly crimes or just oiling the social wheels? To find out let's have a look at the original research this number is based on.

Feldman et al. (2002) told 121 participants they were going to have a chat with someone new for 10 minutes. Then half were divided into 3 groups, each with different goals from the conversation:

1. Competence: try to present yourself so that the other person thinks you're are competent.
2. Likeable: try to present yourself so that the other person thinks you are likeable.
3. Control: no specific goal.

All the participants were secretly videotaped during the conversation then, afterwards, asked to point out their own lies. They were told that lies include things like falsely agreeing with others and the misrepresentation of feelings. Then, while watching the video, they wrote down all the instances of their own lying.

The tangled web we weave

The very first thing to say is that 40% of people claim to have told no lies whatsoever. Whether you believe them or not is a different matter, but it's probably not that far from the truth, after all there wasn't that much motivation to lie in the first place. It was just a bit of chit-chat in the lab, it's not as if they were trying to cover up a murder.

The other 60% did report some lies, though, with the average number being just under 3 in the 10 minutes. The lies they told were categorised as either subtle, exaggerations or outright lies. The most popular category of lie was the outright lie.

Lies were also categorised as to whether they were self-oriented or other-oriented with men telling more self-oriented lies than women. Overall, though, men and women told about the same number of lies, contrary to the popular conception that men are bigger liars than women.

But what, exactly, did they lie about? Lies were categorised by the researchers into 5 areas: feelings, achievements, plans, explanations and facts. Below is the breakdown for women and men in each of the 3 conditions: the control group, the group asked to appear likeable and the group asked to appear competent (these are averages for the 10 mins).

As you can see the most popular category was feelings which, in this study, included lies about emotions, opinions and evaluations. Lies about feelings were particularly pronounced when women wanted to appear competent and when men wanted to appear likeable. This is a well-known finding: people are often found to lie more about their feelings than anything else.

White lies

Lies about feelings are interesting because they are not something we prototypically think of as outright lies. For example when I meet you I might ask: "How are you?" and you might reply "Fine" when actually you feel like crap. Technically that is a lie. But there is also a social convention at work here; especially if you're a stranger I've just met. You understand that I don't want to know exactly how you are, it's a social nicety.

The question is: what is the moral dimension? The kind of lies we find most detestable are those with a malicious intent of some kind: lies designed to swindle or hoodwink us, lies that will cause us some pain down the road. Yet many lies about feelings are motivated by the exact reverse, they are quite often pro-social lies.

In this study we could just as easily argue that all the apparently 'bad' lying people are doing may well be of the 'good' pro-social sort. This may be especially true in the motivated goal conditions where people are managing their self-presentation to oil the social wheels.

So maybe many people do lie within minutes of meeting someone new, but as Dr House vividly demonstrates, an unceasing quest for the truth in daily life is asking for trouble. Without the lies we tell each other our social lives would be a lot more painful. In fact many of our lies show what nice, well-adjusted people we are.

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PsyBlog is now on Twitter, right here.

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Say you want to create a new habit, whether it's taking more exercise, eating more healthily or writing a blog post every day, how often does it need to be performed before it no longer requires Herculean self-control?

Clearly it's going to depend on the type of habit you're trying to form and how single-minded you are in pursuing your goal. But are there any general guidelines for how long it takes before behaviours become automatic?

Ask Google and you'll get a figure of somewhere between 21 and 28 days. In fact there's no solid evidence for this number at all. The 21 day myth may well come from a book published in 1960 by a plastic surgeon. Dr Maxwell Maltz noticed that amputees took, on average, 21 days to adjust to the loss of a limb and he argued that people take 21 days to adjust to any major life changes.

Unless you're in the habit of sawing off your own arm, this is not particularly relevant.

Doing without thinking

Now, however, there is some psychological research on this question in a paper recently published in the European Journal of Social Psychology. Phillippa Lally and colleagues from University College London recruited 96 people who were interested in forming a new habit such as eating a piece of fruit with lunch or doing a 15 minute run each day Lally et al. (2009). Participants were then asked daily how automatic their chosen behaviours felt. These questions included things like whether the behaviour was 'hard not to do' and could be done 'without thinking'.

When the researchers examined the different habits, many of the participants showed a curved relationship between practice and automaticity of the form depicted below (solid line). On average a plateau in automaticity was reached after 66 days. In other words it had become as much of a habit as it was ever going to become.

This graph shows that early practice was rewarded with greater increases in automaticity and gains tailed off as participants reached their maximum automaticity for that behaviour.

Although the average was 66 days, there was marked variation in how long habits took to form, anywhere from 18 days up to 254 days in the habits examined in this study. As you'd imagine, drinking a daily glass of water became automatic very quickly but doing 50 sit-ups before breakfast required more dedication (above, dotted lines). The researchers also noted that:

• Missing a single day did not reduce the chance of forming a habit.
• A sub-group took much longer than the others to form their habits, perhaps suggesting some people are 'habit-resistant'.
• Other types of habits may well take much longer.

No small change

What this study reveals is that when we want to develop a relatively simple habit like eating a piece of fruit each day or taking a 10 minute walk, it could take us over two months of daily repetitions before the behaviour becomes a habit. And, while this research suggests that skipping single days isn't detrimental in the long-term, it's those early repetitions that give us the greatest boost in automaticity.

Unfortunately it seems there's no such thing as small change: the much-repeated 21 days to form a habit is a considerable underestimation unless your only goal in life is drinking glasses of water.

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