Personality: What Makes You the Way You Are (Oxford Landmark Science)

This book is different from most books on personality development because it looks at differences in personality acquirement from an evolutionary perspective. Why should people have different personalities? The reason, it states, is that at different times during our evolutionary history certain personality styles have been more advantageous to have as compared to others. For example, sometimes it would have been advantageous to be neurotic and act in a cautious manner, but sometimes it would have been advantageous to be an extrovert and act daringly.Once a certain type of personality style evolved during the course of human evolution, the genes responsible for that personality style were maintained in the gene pool (the entire genetic composition of a species) by natural selection, if indeed that personality style was advantageous to the survival of the individuals who possessed it. For example, why should certain people have a neurotic personality style when, at least from a social point of view, neuroticism is not associated with having a winning or advantageous personality? The answer is that the way neurotic people behave has been beneficial to their survival (or from an evolutionary perspective, the way neurotic personalities behave at certain times has caused them to have more offsprings during the course of evolution and outcompete other individuals with a different personality styles who may not have had as many offsprings).The above assertion is based on the concept of "fluctuating selection". From a behavioral perspective, during the course of evolution (of various species on earth), natural selection does not constantly favor the same type of individuals who behave a certain way; if it did, all individuals in that species eventually would behave the same way. The way that the natural selection works [or the way that it picks individuals to represent their genome (the genetic composition of each individual) in the next generation] fluctuates due to environmental conditions. For example, sometimes it would have been advantageous to wonder off a long distance from the base camp to hunt animals, the way an extrovert might do things, because the human predators were low in number, and there was a little chance to encounter them. However, some other times it would have been better to hunt around the base camp, the way a neurotic may act, since there were a large number of human predators around. During the latter time, if the extroverts were acting the way that they usually do, they may perish (and not have any opportunity to reproduce). From the above discussion, we can conclude that because natural selection has been fluctuating, it maintains many different types of behaviors and personalities in human populations.Another conclusion is that personalities have a genetic basis rather than an environmental one. This has been supported by identical twin studies. When behavior scientist would like to distinguish whether a trait has a genetic or environmental basis, identical twins are used. The reason is that identical twins have identical genomes so if a trait is different among them it can be attributed to the possibility that they had a different environment. Often, in genetic-behavioral studies, identical twins that were raised in different families (and had no contact with each other) are used because the experimenter wants to know if they behave differently because they grew up in different families and environments. The so-called "identical twins reared apart" experiments that have been conducted so far mostly indicate that personality styles are actually genetic since the twins that are raised apart still have the same personality.How can environment not have any effect on personality development? The whole field of analytical psychology is based on the assumption that it is your parents and environment that have shaped your personality and if you can understand your environment in the past, you can understand your personality better and that would serve as a basis to cognitive, emotional, or behavioral change, if such is required. However, the above conclusion with the twins does not mean that you cannot change your personality once you understand yourself better, but it does mean that your genetics determines your personality not your environment. That is still a conclusion that does not make sense. What about all the experiments that do show that environment have a drastic influence on personality development, not to mention our own personal experiences with our environment that we have assumed have shaped our personalities. I think it is still too soon to conclude anything from the above twin experiment. Maybe the effect of the environment was somehow lost due to the twin populations that were supposedly chosen randomly or the way the experiments were designed. I think we should wait to draw conclusions after further studies have been conducted the may clear the above results.The rest of the book concentrates on explaining the five-factor model of personality. This personality model was based on a statistical method called factor analysis. Research scientist studying personality took thousands of adjectives and words that describe different personality traits and saw that using statistical correlation they are able to place these personality traits into only five major personality style categories. In other words, they saw that many of the personality traits can be correlated with each other, are redundant, and describing the same personality style. For example, they saw that the personality traits such as outgoing, social, talkative, competitive, enjoys a lot of sex and romance, interested in travel could be all correlated with behaviors that a person who is extraverted would exhibit, thus they made "extraversion" into one of the five personality style categories.The five personality styles and their description are:1- Extraversion: A personality style possessed by someone who is usually enthusiastic, energetic, talkative, outgoing, adventurous, risk-taker, outwardly focused, loud and talkative, self-confident, very interested in sex and romance, a leader, active in sports, ambitious, competitive, usually looking for fame, fortune, and status, interested in travel and leisurely pursuits, and impulsive and spontaneous. Generally, an extravert has many positive emotions and is usually optimistic.2- Neuroticism: A personality style possessed by someone who is usually emotionally reactive, a worrier, prone to stress, anxiety, and depression, not emotionally stable, insecure, inwardly-focused, sensitive, feeling guilty, aloof, quiet, and self-conscious and shy. Generally, a neurotic person has many negative emotions and is usually pessimistic.3- Conscientious: A personality style possessed by someone who is usually organized and likes order, self-disciplined, detail-oriented, a planner, careful, achievement-oriented, self-directed, dutiful, and controlling. Conscientious individual may have a tendency for obsessive-compulsive disorder.4- Agreeableness: A personality style possessed by someone who is usually cooperative, trusting, empathetic, compassionate, friendly, generous, helpful, willing to compromise, and optimistic.5- Openness: A personality style possessed by someone who is usually imaginative, inventive and creative, curious, art-enthusiast, seeker of various experiences, aware of their feelings, self-reflective, eccentric in some views, and a user of complex words.It is important to mention that individuals often possess all of the five personality styles but to different degrees. It is very rare that a person could be described by only one personality style.

I've always known I'm not like my family and friends. In our circle I'm definitely the odd man out. And I've known this since I was 19 or 20 years old. So fairly early in my life I was interested in why I was different, why I didn't mind being different, and why I always struggled when I tried to just fit in. I've read Myers-Briggs and other "modern" models of personality and took interest in them. And in them I usually found some nuggets of explanatory wisdom. So I had largely stopped reading about personality.But I casually glanced at Nettles' book one day and found myself thinking, "A new model of personality? One with widespread support and evolutionary underpinnings? Damn. I'm going to have to read it."And I'm glad I did. First, this book fills a void. Most psychology books for a consumer audience are so watered down and trite they fail to really teach anything. They're usually worse than the drivel you find in Cosmopolitan or Men's Health. Try searching for psychology books with a more intelligent bent to them and you quickly find yourself shoulder-deep in academic, jargon-laden prose. Nettles' book is a brilliant bridge between these two worlds. Personality: What Makes You The Way You Are is an excellent presentation of a newer model of personality theory. It is rich in back-story, supported by summaries of various experiments, bolstered by real statistical concepts instead of dumbing it down to "the average", and keeps itself wrapped in an evolutionary biology framework. And it does all of this without getting overly academic.For those who lean toward Cosmopolitan and Men's Health, Nettles includes a personality inventory you can self-administer, and it makes the content of the book more personally relevant. Personality is also a quick read (I read through it on two flights between Minneapolis and Salt Lake City). And the book is laced with humor throughout.For those who prefer academia, Personality is well-referenced and has a comprehensive bibliography and set of appendices. It is solid and honest academic work; it just reads better.About the only warning I'll make is this: Nettles is a Brit. If you get confused by British spellings, idiom, and geographical references, you may occasionally find yourself scratching your head. But all this tells me is you don't read enough Nick Hornby.Enjoy! I believe you will.

Suppose you ask people to rate their interest in such things as social activities, travel, competitive success and sex. Perhaps not surprisingly, their separate scores will correlate with each other (0.1 - 0.3). If you now ask them whether they ever feel depressed or `blue', or whether they have sought help for anxiety, their scores for these two items also positively correlate with each other. But the first four sets and the second two sets don't cross correlate at all. This suggests there are deeper traits at work. A technique called factor analysis identifies Extraversion as the common factor in the first set, and Neuroticism as the common factor for the second. These two factors are independent.When a wide variety of personality-relevant items are rated for large samples of people, factor analysis reliably and repeatedly confirms that there are five underlying, independent personality traits: Extraversion and Neuroticism as already described; Conscientiousness, Agreeableness and Openness. Each will get a chapter to itself.The Five Factor Model of personality is often accused of shallowness, and of being atheoretic as the factors simply emerge from statistical processing (in fact just the same factoring procedure generates the g-factor - general intelligence - as measured through IQ tests). The great strength of Nettle's book is that he can link individual variation within each of the five factors to differences in brain anatomy and metabolism as captured by MRI scanners and then with genetic differences. The five traits seem to be capturing something real about genetically-determined brain variation.Common observation confirms that we are surrounded by different personalities. If personality is heavily determined by our genes, as it appears, then why haven't we all converged on an ideal personality? You can, of course, ask the same question about any continuously-varying trait which still exhibits variation, such as height or intelligence. The answer seems to be a combination of environmental instability (rewarding different parts of the variability-spectrum in different circumstances) and frequency-dependent selection (as in the way a few rather nasty people can take advantage of the many nice-but-gullible). Nettle discusses this in detail - it will be a recurring point that all positions in personality space help in some circumstances but hinder in others.The chapter on Extraversion, setting a pattern for those to come on the other traits, links the behavioural attributes of extraverts with brain imaging and genetic studies. Extraversion, it turns out, comes down to a strong reaction to positive emotions - those feelings we find rewarding; introverts just don't seem to care so much, conserving their energy. There seems to be a link between extraversion and genetic variation in sensitivity to dopamine.Neuroticism, by contrast, relate to sensitivity to negative emotions: to score highly on this dimension is to be a worrier. The associated brain chemistry seems to involve the neurotransmitter serotonin: inhibitors such as Prozac seem to make us less worried about life's many sources of anxiety.Conscientiousness, the third trait to be analysed, seems at first sight a pretty good trait to score highly on. It's the most reliable predictor of occupational success across the board. Conscientiousness is particularly valuable in structured, rule-based environments such as we find in advanced technological societies. Change the situation to one of unpredictable, fast-changing circumstance however, and the rule-bound are at a disadvantage. The army, for example, has a continual internal conflict as it needs both sorts, but they continually rub each other up the wrong way.Agreeableness, the fourth dimension, sounds like a trait well-worth having. Who could fault being nice? Perhaps not so strangely, success in business correlates with low scores on this trait. Something about putting other people first and a degree of self-effacement doesn't sit easily with tough, mission-oriented leadership. This is the one trait where female and male scores are clearly distinct, with women scoring more than half a standard deviation higher in agreeableness. There is a ready evolutionary explanation in the pre-modern sexual division of labour.The final dimension is Openness to Experience. This is a hard dimension to pin down. Some people equate it with intelligence, but the author is of the opinion that intelligence is a kind of whole-brain efficiency measure implicated across all areas of neural functioning including such non-intellectual tasks as pure reaction times. Nettle believes high-scorers on Openness are artistic, creative people capable of making associations between different - and perhaps surprising - kinds of things. Intellectuals on the science, technology, engineering and maths front don't look much like famous poets and acclaimed authors. Wherein lies the difference? For once the author doesn't have good answers, believing the key to excellence in these STEM subjects is more down to general intelligence. But clearly that can't be the whole story.In the final part of the book the author reviews the evidence for `environmental' influences determining personality and finds they are few and hard to find. Family and parental input (if non-abusive) has been carefully measured to have exactly zero impact: you can't change your child's personality. Does this give people a deterministic get-out - my genes made me do it? In the final chapter Nettle carefully demolishes this view, showing that dispositions are one thing, but the life choices you make to go with or against the flow of your dispositions are something else.In summary, this book is a wonderfully accessible and profound exploration of the concept of personality. Everyone will learn something about themselves from reading it and it conclusively takes us beyond the limitations of the Jungian approach as in Myers-Briggs theory. There is a short 12 item questionnaire which you are encouraged to take before reading.

I loved Nettles open and easy-to-read writing style, making a topic which broaches topics and ideas of such complexity a joy and breeze to read. I was recommended this book and thouroughly enjoyed it. It made me ponder about many aspects of personality and the way it is effected by enviroment, evolution and genetics considerably. I particularly enjoyed his chapters on the Big Five personality traits. It really delves you into yourself and makes you understand why you are the way you are. I have always questioned the idea of personality and Nettle illustrates it all so simply. He does this in a way which doesn't state anything subjectively, but with scientific research and evidence. I loved how he explained elements of personality in evolutionary terms, which is something I hadn't thought of affecting personality. To summarise, he gives you your own personality test too. With this and the rich information provided about personality you can finally plunge into the depths of yourself, understanding who you are and why.

I thoroughly enjoyed reading each chapter of this book, which is written in exceedingly clear language. Il felt like each point was explained in the precise number of words and that any additional ones would be superfluous - even tough the author would probably be able to develop a whole chapter for each sentence. A fascinating book for anyone seeking to better understand themselves and others, with an overall very positive message that no personality type is better or worse than another but that we can try to find the most positive outlets to express our inherent, unchangeable traits.

He definitely knows his stuff and he keeps to a clear line and argues the case for it very well.Personally, I'm not sure I can agree with some of the more deterministic approaches (he almost dismisses family environment as a factor in personality formation, which I struggle to accept) but that's my view and doesn't detract from a well-researched, very accessibly written and compact book.As popular psychology goes, Nettle has done a good job of sticking to the topic and making it digestible, without dumbing down or wandering off course. Definitely worth a read.

Good book. Detailed accounts of all traits, including advantages and disadvantages of each one, though I felt the author really delved deep into disadvantages for conscientiousness and ignored its advantages a bit. The advice at the end about finding your niche based on your personality is highly useful.