Extrovert: yellow 24%, gold 24%, orange 19%, red 14%, …
Heller (1989)

People who score high on activity are generally bussy and energetic. They love all kinds of physical activities, hard labour and physical exercises included. They get up early and quickly, jumping from one activity to another and have a wide range of interests. People with low scores are physically inactive, lethargic and easily tired. They always move at a calm pace and prefer quiet and calm holidays. High activity is a characteristic of the extrovert and low of the introvert.
Eysenck, H. J. (1998)

Introverts are more aroused in the morning and extraverts are more aroused in the evening.
(Revelle et al., 1980)

Introverts have a higher temperature in the morning but by late afternoon and evening extraverts have the higher body temperature.
(Blake, 1967)

Moderate doses of caffeine hindered the performance of introverts and helped the performance of extraverts on a cognitive task. However, these phenomena were affected by time of day and impulsivity. Low impulsives are more aroused in the morning and less aroused in the evening than are the high impulsives.
(Revelle et al., 1980)

Extrovert people seem to have a preference for red, orange and yellow.
Heller E. (1989)

Women are less extravert and emotionally less stable than men. (Eysenck, H. J., 1998)

Impulsivity (as opposing to reflectivity) correlates quite well with extraversion, but even better with psychoticism
(Eysenck & Eysenck, 1985)

De bi-polaire termen introversie en extraversie werd ingevoerd door Carl Jung die ze gebruikt als kern van zijn persoonlijkheidsprofielen. Hans Jürgen Eysenck (1998) gebruikte deze antagonisten als meest belangrijke merker in zijn persoonlijkheidstheorie.
·- Met een extraverte ingesteldheid is de energie naar buiten gericht, op mensen, activiteiten en dingen.
– Met een introverte ingesteldheid is de energie naar het innerlijke zelf gericht, op eigen ideeën en gevoelens.

Preferred stimulation levels in introverts and extraverts differ and has effect on arousal and performance. Introverts have an increased sensitivity to stimulation and choose a lower level of noise than do the extraverts, and both introverts and extraverts show no difference in arousal and performance with preferred noise level.
(Geen, 1984)

Reward Dependence reflects a heritable bias in the maintenance of behaviour in response to cues of social reward. It is observed as sentimentality, social sensitivity, attachment, and dependence on approval by others. Reward Dependence corresponds with Eysenck’s introversion-extraversion trait.
Low Reward Dependence: independent, non-conformist, practical, tough-minded, cynical, unwilling to share their intimate feelings with others, socially detached, irresolute, insensitive to social cues and pressures, content to be alone, minimally motivated to please others, act for immediate gratification, social withdrawal, with aggressive anti-social behaviour detachment, coldness in social attitudes. Individuals low in Reward Dependence are practical, tough-minded, cold, socially insensitive, irresolute, and indifferent if alone.
High Reward Dependence: sentimentality, Openness to warm communication or social sensitivity, Attachment, Dependence on approval by others, greater need for social rewards and verbal approval, ambitious, warm, warm social relations, sentimental, pleasant, sociable effective communication, sensitive, recognize salient social cues, sympathetic, genuine care for others, socially dependent, persistent behaviours, easily influenced by emotional appeals, learning from reward signals, persisting repetition of actions that are associated with rewards, increased sociability and a need for social approval. Individuals high in Reward Dependence are tender-hearted, sensitive, socially dependent, and sociable.
(Cloninger, 1994)

You can see seven traits that correlate with each other, i.e. people who are sociable, impulsive, active, risk-taking and expressive, and lacking consideration and responsibility. This combination of character traits produces a new and more general character that is called extraversion.
(Eysenck & Wilson, 1977)

Introverts perform better than extraverts under low levels of stimulation but perform worse at high levels of stimulation.
(Eysenck, 1967)

Extroverts use less words that express negative emotions, and more words about friends and family. A report of an event will be presented subjectively and with its own interpretation. Extroverts use relatively more adjectives to describe behavior and less concrete descriptive action verbs. They often have lively and cheerful conversations in which they discuss multiple topics in a loose way. Extraverts process information in a global way. A looser way of looking at the world is related to a large degree of interpretation. They speak and respond more quickly in a conversation, but they are less scrupulous about the facts.

While introverts will provide a concrete and factual description, with fewer adjectives and more descriptive action words. They are often more serious in conversations, and focused on one subject. They process information precisely and focused. Introverts thinks well before they speak. This also fits with slower speaking, more frequent breaks and more precise formulation.
Beukeboom (2011)