The scientific study of human individual differences is a cornerstone subject area in modern psychology (Maltby, Day, & Macaskill, 2010). It is Plato’s statement more than 2000 years ago, “no two persons are born exactly alike” (Nazimuddin, 2015, p. 183-184), that highlighted the need to consider individual differences in constructing new psychological theories Sir Francis Galton’s invention, psychometrics, is the initial inspiration for the development of various techniques of present psychological measurements (Jensen, 2011). However, it was James McKeen Cattell, who expanded Galton’s work, that was responsible for the development of modern psychological tests (Kaplan ; Saccuzzo, 2005). Personality and intelligence are two popular area of modern individual differences studies. In fact, the first psychometric instruments were designed to measure the notion of intelligence (Jensen, 2011). Intelligence testing is aimed at measuring individual’s cognitive ability to acquire and apply knowledge while personality testing is aimed at identifying the various aspects of the personality or the emotional status of the individual (Maltby, Day, & Macaskill, 2010; Domino & Domino, 2006). Today, researchers agree that we can classify people according to their intelligence and personality characteristics with moderate success, however, since people are complex, there are multiple and often conflicting theories and evidence in this area of study (Furnham & Dissou, 2007).
History of personality research
Galton is one of the first researchers to apply lexical hypothesis to personality research. Lexical hypothesis denotes that consequential personality characteristics of a group are more likely to be encoded into the group’s language as a single term (Block, 2010; Uher, 2013). Early explorations in personality psychology, therefore, ventured into the “psycholexical” classification of personality traits (Wood, 2015). From the late 19th century to the early 20th century, the use of lexical hypothesis flourished in English psychology (Domino ; Domino, 2006).
In 1936, Allport and Odbert proposed an influential psycholexical studies in trait psychology. They identified 17,953 terms describing personality or behaviour, grouping them into four separate columns: neutral terms, temporary moods, social judgements and metaphorical terms (Allport ; Odbert, 1936). Many of their terms could have been differently categorised or placed into multiple categories and their work was criticised for being somewhat inconsistent and incomplete (Uher, 2011). It was in 1943, when a British and American psychologist, Raymond Cattell used factor analysis to investigate the overarching structure of the trait terms. Factor analysis is a statistical procedure for identifying hidden or overlapping patterns to reduce many variables into fewer numbers of factors (Thurstone, 1934; Cattell, 1952).
Applying factor analysis to personality, Cattell discovered 16 primary trait factors within the normal personality sphere and he constructed a self-report instrument using his trait factors, known as the Sixteen Personality Factor Questionnaire (16PF) (Domino ; Domino, 2006). Later, he factor-analysed his 16 primary traits and found five secondary traits, now known as the Big Five. Following this, Dr Hans Eysenck (1970) proposed a three-factor model of Psychoticism, Extraversion and Neuroticism, also known as the PEN model (Boyle et al., 2016; Goldberg, ; Rosolack, 1994). In 1976, Hans and Sybil Eysenck developed the Eysenck Personality Questionnaire (EPQ) to measure the traits described in the PEN model of personality.
The development of the final Big-Five factors began in 1963 when Norman replicated Cattell’s work (Costa & McCrae, 1985). He factor-analysed the 16PF and suggested that five factors were enough. Like Norman, at least three other group of researchers independently identified the same five factors of personality (Domino & Domino, 2006): Ernest Tupes and Raymond Christal in 1961 (Tupes & Christal, 1992), Goldberg at the Oregon Research Institute (Goldberg, 1990) and Costa and McCrae at the National Institutes of Health (McCrae & Costa, 1987). Although these sets of researchers used different methods in finding the five traits, each of the sets of traits was found to be “highly inter-correlated and factor-analytically aligned” (Grucza & Goldberg, 2007). Each set of traits comprises of two opposite but correlated aspects under the broad domain of trait (Paunonen & Ashton, 2001). The final renown five-factor model (FFM), now used in the Big Five Inventory (BFI), is made up of the dimensions of Agreeableness (friendliness and likeability), Conscientiousness (reliability and willingness to achieve), Negative Emotionality or Neuroticism (volatility vs. stable mood), Extraversion (sociability), and Openness or Open-mindedness (broad-mindedness and creativity) (DeYoung, Quilty & Peterson, 2007).
History of intelligence research
Galton was one of the first scientists to study intelligence in the late 1800s. He believed differences in individuals can be measured scientifically and attempted to measure intelligence through reaction time tests (Simonton, 2003). He introduced the use of questionnaires and surveys for collecting data for his studies (Galton, 1869). His success forms the basis for many later researchers in intelligence testing. At present, psychometrics is applied widely in educational assessments to measure linguistics and logical abilities (Goldstein, 2012).
The first intelligence test, known today as the Stanford-Binet IQ test is developed by Frenchman Alfred Binet in the 20th century and is the basis of modern-day intelligence tests (Simonton, 2003). With the assumption that intelligence develops with age but the individual’s cognitive standing remains stable in comparison to peers, he designed a questionnaire that could distinguish children of all ages with learning disabilities (Becker, 2003). The test used a single number, known as the intelligence quotient (or IQ), to illustrate an individual’s score. However, Binet suggested that intelligence is a broad concept, unquantifiable by a single number. He insisted intelligence changes over time and is influenced by several factors and thus is comparable only with children with similar backgrounds (Dale et al., 2014).
Throughout the years, researchers proposed a variety of theories to explain the nature of intelligence. Charles Spearman is a British psychologist who introduced the concept of general intelligence or g factor (Spearman, 1904). His claims include people who perform well in one cognitive test also perform well in the other, indicating intelligence is a general cognitive ability that can be measured (Thomson, 1947). By way of contrast, a theory by Psychologist Louis Thurstone claimed that intelligence is a made-up of seven different primary mental abilities (Thurstone, 1934). This had let to Howard Gardner’s theory of multiple intelligences recently today. He outlined eight distinct types of intelligence, namely, Visual-spatial intelligence, Verbal-linguistic intelligence, Bodily-kinesthetic intelligence, Logical-mathematical intelligence, Interpersonal intelligence, Musical intelligence, Intrapersonal intelligence, and Naturalistic intelligence. He declared that quantifying human intelligence is an inaccurate way to measure people’s abilities (Visser, Ashton, & Vernon, 2006). While many educators and school administrators were inspired by Gardner’s theory, many others from the field of education and psychology criticised his work for the lack of empirical evidence (Klein, 1998). Nevertheless, his work remains popular among educators today (Diessner, 2001).
Personality and Intelligence will be measured using the online versions of the tests. The Big Five Project Personality test (John, 2000) will be used to measure personality which uses a 5-point Likert scale to determine how strong you agree with each of the 60 statements about yourself in various situations. The scale ranges from strongly disagree (1) to strongly agree (5), which generates results in percentiles. Multiple Intelligences for Adult Literacy and Education (Multiple Intelligences for Adult Literacy and Education, n.d.) is a 56 statements questionnaire, utilised to measure different intelligence strengths on a 5-point Likert scale, ranging from Statement ¬¬does not describe you at all (1) to Statement ¬¬- describes you exactly (5) (1992). The questionnaires used in the test can be found in Appendix A and B. The results from the two psychological tests will be evaluated and discussed later in the “Evaluation and Reflection” section.
Figure 1 and 2 show the results of the Big Five Project personality test and the Multiple Intelligence tests produced from the two separate attempts. The first attempt was on Tuesday, 8 May 2018 at 10 am and the second attempt, on Saturday, 19 May 2018 at 10 am. It is necessary to note that during the first attempt, I was in a balanced mood at work and during the second attempt, I was in a considerably bad mood.
BFI scores on the Big Five Personality test
According to Figure 1, the BFI score was highest for Open-mindedness in both attempts (90%, 84%) and lowest for Extraversion (26%, 38%). The scores for Conscientiousness and Negative Emotionality were also high (above 65%), with Agreeableness considerably increasing from 50% to 74% in the first and second attempts.
Intelligence scores on the Multiple Intelligence (MI) test
As Figure 2 shows, in both attempts, Social Intelligence score was the highest (3.71, 4) and the Spatial Intelligence score was the lowest (2.43, 2.86). The scores for other types of intelligence were also persistent across two attempts and they range from 3.71 to 2.71. ?
Evaluation and Reflection
Results from the Big Five Inventory (BFI)
The results from the BFI test did not come as a surprise for me. This is because I have taken the test before and knew that I will score high in Openness, Agreeableness and Negative Emotionality and low in Extraversion. However, my scores for Conscientiousness are now higher than the previous score I remember (; 50%).
Open-mindedness covers a broad range of traits associated with intellectual curiosity and an adventurous mien and open-minded individuals are described as intellectual, unconventional, independent and imaginative (McCrae ; Costa, 1987; Zuckerman, 1994; p. 31). The high score on this trait reflects my personality as I love learning and exploring new cultures and activities. Open-mindedness is defined by Authentic Happiness Coaching (2004) as being readily acceptable and in search of knowledge or truth that is outside one's own beliefs such as alternate religious beliefs. Being an atheist despite coming from a religious family shows that I am open to disparate ideologies and thus, scoring high in this trait. In addition, research has suggested that multicultural exposure is linked to openness in individuals (Leung ; Chiu, 2008; Livert, 2015; Chao, Kung ; Yao, 2015; Maddux ; Galinsky, 2009). Not only did I grow up in an Asian family and went to an International school, I have lived and studied in three different countries in my life. A high score in openness (90% and 84%) is therefore accurate in my case. Similarly, in 2015, I??k and Üzbe performed an analysis of meaning in life among adults and found that individuals who are open to experiences search for meaning and purpose of life and adhere to ventures that serve these purposes. Since I am working towards changing my career from a public relation specialist to a clinical psychologist, it is obvious that I am devoted to helping people, something I believe is my purpose in life. Scoring high on this trait is, therefore, illustrative of my personality.
Conscientiousness captures individual differences in the degree of organisation, persistence and motivation to succeed goals (Bartley, ; Roesch, 2011; Duckworth, Weir, Tsukayama, ; Kwok, 2012). High conscientious people are self-disciplined, focused, persistent and goal-driven (Packer, Fujita, ; Herman, 2013; Hülsheger ; Maier, 2010). I have been told I am determined and that I have high standards by the people around me recently, contrary to what I used to be when I was younger. Oliver, Guerin, ; Coffman (2009) studied the effect of the big five parental personality traits on their offspring and found that children of conscientious mothers are predisposed to the trait themselves. This suggests that having hard-working parents is the reason I scored moderately high in Conscientiousness (76% and 72%). Additionally, research has shown that the average level of conscientiousness escalates as a person ages, usually from adolescence to middle age, due to the increasing demands of adult roles (Caspi, Roberts, ; Shiner, 2005; Lucas, ; Donnellan, 2011; Wu, 2016). As I transitioned from being a fresh graduate to a working adult, it was obvious that I had to step up to fulfil my adult roles both at home and work. Naturally, this explains why my conscientiousness scores have increased now compared to the past.
A low score on extraversion (26% and 38%) implies that I prefer solitude over spending time socialising with others, i.e. an introvert (Shatz, 2005). While it was true that I prefer to spend most of my time alone, I was not convinced the first time I took the test because I periodically enjoy going out with family and friends, having discussions with them and taking part in fun activities. I previously suspected I may be an ambivert, which is in between the introvert and extrovert extremes (Davidson, 2017). However, Cooper (2013) identified the ;signs that point someone closer to an introvert; (p. 13), and highlighted that while they need alone time, introverts enjoy one-on-one time or in small groups with family and close group of friends regularly. They also pointed out that introverts are not always shy, they take part in social activities, giving that they shall get some quiet time after to recharge. Hence, I am convinced that my scores are accurate and that am closer to being an introvert than an ambivert.
Agreeableness is associated with traits such as being kind, generous, sympathetic and trusting of other people (Barrick, Mount, ; Judge, 2001; Costa ; McCrae, 1992). In Buddhism, compassion for others is the heart of its teachings (Goodman, 2014). Therefore, being empathetic and having a concern for others is engraved in the personality of Buddhist followers like me and thus, possessing an above-average level of the trait (Ark, 2014). Besides, longitudinal studies such as Furnham and Cheng (2015) highlighted that females consistently score higher than males in Agreeableness across ethnic groups (Weisberg, DeYoung, ; Hirsh, 2011). Despite the claims, as mentioned above, my scores for Agreeableness is moderate in both attempts (50% and 60%). I agree that previous working experience in the business field has taught me to be more focused on the tasks and less on other people, hence, I hold a balanced level of agreeableness.
Lebowitz (2016) proposed individuals high in Negative Emotionality or Neuroticism are vulnerable to anxiety, depression, worry, and low self-esteem. Neuroticism encompasses emotional stability and general temper of a person (Judge, Erez, Bono, ; Thoresen, 2002). It is likely no surprise that people high in this trait do not produce one's best work. Generally, Neuroticism was found to be inversely correlated with other Big Five (Ones, Viswevaran, ; Reiss, 1996). In fact, a long-term study by Soldz and Vaillant showed that Neuroticism is linked to addiction, alcohol abuse, low resilience and mental health issues (1999). By contrast, I scored moderately high on Negative Emotionality and on other traits except for Extraversion as well. Also, since I regularly meditate and do yoga to manage my thoughts, I predicted my score to be moderate on this trait (Giluk, 2009). For this reason, it would be useful to explore other sub traits of Negative Emotionality to help identify the reason for the score (Roccas, Sagiv, Schwartz, ; Knafo, 2002).
The Multiple Intelligence (MI) Test Results
I find the results of the MI test to be somewhat accurate. The results claimed I am mostly socially intelligent and least intelligent spatially.
Gardner (1993) has identified the two aspects of personal intelligence as social intelligence and intrapersonal intelligence. Social intelligence is measured by the capacity to detect moods and respond appropriately to others and individuals strong in social intelligence are good at understanding and interacting with other people (Summerfield, Kloosterman, Antony ; Parker, 2006). Intrapersonal intelligence is defined by the degree of self-awareness and being in tune with one's feelings, values, beliefs and thinking processes (Gardner, 1993). I believe being socially intelligent and self-aware are the reasons for my career and personal success today. Jacobs (2004) (in Pearson, 2011) has proposed that personal intelligence is a necessity for clinicians. My ambition to dedicate myself to helping others and becoming a clinical psychologist, I believe, is the result of having high interpersonal and intrapersonal intelligences.
Researchers suggested links between logical-mathematical intelligence and spatial intelligence (Tirri, ; Nokelainen, 2008). On the contrary, I scored high in logical-mathematical intelligence but the lowest in spatial intelligence. Generally, individuals with this intelligence are good at reasoning and comprehending abstract concepts (Tirri ; Komulainen, 2002). Spatial intelligence measures the ability to visualize and work with multidimensional objects (Gardner, 2017). Having a background in business and engaging in scientific research currently in the MSc Psychology programme explain why I have scored high in Logical-mathematical intelligence. However, it is not clear why I have scored lower on Spatial intelligence when I have been driving a car for two years now.
Limitations of BFI and MI tests
While no psychological tests are free from censure, BFI and MI have been criticized on one ground or another (Furnham ; Dissou, 2007; Trofimova, Robbins, Sulis, ; Uher, 2013). First, Pervin (1993) and Mischel and Shoda (1995) claimed that reliability of psychological tests depends upon the individuals, circumstances, situations and the parameters adopted for the experiment. In contrast, results of the two psychological tests (John, 2000; Multiple Intelligences for Adult Literacy and Education, n.d.) were different between the two times the tests were taken, even when the environment and the timing of the test were controlled. Secondly, the Big Five is not based on an underlying theory, but simply a data-driven description of traits (Boyle, 2008; Trofimova, Robbins, Sulis, ; Uher, 2013). Similarly, to date, no published studies have offered evidence of the validity of the MI and Gardner (2004) admitted that there is ;little hard evidence for MI theory; (p. 292). Evidently, the reliability and validity of the tests remain low.
Social desirability bias and mood effects should be addressed when using self-estimate methods (Arendasy, Sommer ; Schutzhofer, 2011; Furnham ; Dissou, 2007). Researchers claim that people give responses to different descriptions because they wish to see themselves as described (Robins et al., 2001). In addition, evidence shows that an individual's mood can affect their responses (Jylhä, Melartin, Rytsälä, ; Isometsä, 2009). In 2009, Matthews and colleagues analysed the personality-mood relationship (also see Jeronimus, Kotov, Riese ; Ormel, 2016). The study suggested that neuroticism heavily influences mood states in individuals across situations. This suggests that since I tend to be a neurotic person, the variability in scores between my first and second attempts is explained by my different mood states, possibly caused by factors prior to the experiment (Matthews, Deary, ; Whiteman, 2009). Furthermore, psychologists criticized the MI test, claiming that the accuracy of self-report responses itself depends upon individual's introspective ability (Furnham ; Dissou, 2007; Okada, ; Oltmanns, 2009; Trofimova, 2014). Nonetheless, since I achieved a high score in Intrapersonal intelligence, it can be assumed to not be a serious problem in the study.
Finally, various researchers have raised concerns regarding the Lexical hypothesis in the established five-factor models of personality (Block, 2010; Furnham ; Dissou, 2007; Lamiell, 2003; Linkov, 2016). John, Angleitner, and Ostendorf (1988) criticized the use of lexica of human languages and claimed it may not explain all variations in human personality, thus, translation of the concept in different languages may not reflect the actual meaning of the concept. This suggests that I, being Burmese, may have interpreted the definition of traits in relation to my own language, thus, my scores are questionable. It is evident that there is a serious need for ways to assure validity among cross-cultural studies in personality research (Linkov, 2016).
The tests used in the study were somewhat useful in assessing my intelligence and personality. Some researchers argued Big One or Big Two model be more appropriate (McCrae ; John, 1992), while others are opposed to the idea of personality itself (Doll, 1953). The idea of multiple intelligences is still overshadowed by the g factor theory as many studies show evidence of the underlying mental ability affecting cognitive tasks performance (Castejon, Perez, ; Gilar, 2010; Visser, Ashton, ; Vernon, 2006). Nevertheless, the Big Five and Multiple intelligence tests are some of the most effective tools used to gain insights into our thought processes and actions. They will continue to serve as strong foundations for further studies in individual differences research alongside its evolution.