We each have our own personality – that unique part of us that makes us who we are. It affects every aspect of our lives - from who we date, to what we study, to what we like to do. So what do we know about personality?

1. Birth order can affect our personality: There are traits we associate with being a first born (being bossy, motivated, high achievers or more driven); with being a middle born (being friendly, people pleasers, and quite skilled negotiators); and being a last-born (being amusing, more laid back, and also less responsible). Empirical research supports these norms and trends.

2. There are Five Core Personality Traits: These are measures of extraversion, agreeableness, conscientiousness, neuroticism and openness.

3. Personality remains stable through life: The research findings are less conclusive here. It may be that some core traits are less susceptible to change. However, traits which seem less fixed and less stable over time include anxiety levels, friendliness and eagerness for novel experiences.

4. Certain personalities are more prone to disease: There appears to be a link between one of the “big 5 traits” (neuroticism) and proneness to developing headaches, asthma, arthritis, peptic ulcers and heart disease. There is also a link between having a Type A personality (and, in particular, scoring high on the hostility levels) and developing cancer and heart disease.

5. Our personality affects our personal preferences: The impact here is surprisingly far reaching. It includes: our choice of friends and partner, our taste in music, our political preferences, our career choices, our preferred holiday destinations and so on.

6. People can tell your personality from your facebook profile: Interestingly, although you might expect people to project an ideal online identity, research indicates that facebook profiles actually tend to convey our real personality. Sam Gosling, a key psychologist and author, has explained this in the following way: “I think that being able to express personality accurately contributes to the popularity of online social networks in two ways …First, it allows profile owners to let others know who they are and, in doing so, satisfies a basic need to be known by others. Second, it means that profile viewers feel they can trust the information they glean from online social network profiles, building their confidence in the system as a whole.”

7. There are a number of factors that contribute to personality disorders: An estimated 10 to 15% of adults are diagnosed with at least one personality disorder in their lifetime.  Factors contributing to the onset of these include: Genetics, relationships with family and peers, inheriting high levels of sensitivity, childhood abuse and experiencing a trauma.

8. Your pet may reveal your personality: Many people consider themselves to be either a “dog person” or a “cat person”? Research into pet preference and personality indicates that dog lovers tend to be more extroverted and greater people pleasers, whereas cat lovers tend to be more introverted and curious.