What does the TCI measure?
The TCI measures individual differences in the ways that people feel, act, or behave. These differences are expressed through different individual scores on 7 personality dimensions: 4 dimensions of Temperament and 3 dimensions of Character.

Harm Avoidance - Fear, Behavioral Inhibition
Harm Avoidance involves a heritable bias in the inhibition of behavior in response to signals of punishment and frustrative non-reward. It is observed as pessimistic worry in anticipation of problems, fear of uncertainty, shyness with strangers, and rapid fatigability. People high in Harm Avoidance are fearful, socially inhibited, shy, passive, easily tired, and pessimistic even in situations that do not worry other people. Adaptive advantages of high Harm Avoidance are cautiousness and careful planning when hazard is likely. The disadvantages occur when hazard is unlikely but still anticipated, which leads to maladaptive inhibition and anxiety.

People low in Harm Avoidance are carefree, courageous, energetic, outgoing and optimistic even in situations that worry most people. The advantages of low Harm Avoidance are confidence in face of danger and uncertainty, leading to optimistic and energetic efforts with little or no distress. The disadvantages are related to unresponsiveness to danger or unreasonable optimism with potentially severe consequences when hazard is likely.

Novelty Seeking - Anger, Behavioral Activation
Novelty Seeking reflects a heritable bias in the initiation or activation of appetitive approach in response to novelty, approach to signals of reward, active avoidance of conditioned signals of punishment, and skilled escape from unconditioned punishment. All four of these behaviors are hypothesized to covary as part of one heritable system of learning (Cloninger, 1987). They are observed as exploratory activity in response to novelty, impulsiveness, extravagance in approach to cues of reward, and active avoidance of frustration. Individuals high in Novelty Seeking are quick-tempered, curious, easily bored, impulsive, extravagant, and disorderly. Adaptive advantages of high Novelty Seeking are enthusiastic exploration of new and unfamiliar stimuli, potentially leading to originality, discoveries, and reward. The disadvantages are frequent and easy boredom, excessive impulsivity and angry outbursts, potential fickleness in relationships, and impressionism in efforts.

Persons low in Novelty Seeking are slow tempered, uninquiring, stoical, reflective, frugal, reserved, tolerant of monotony, and orderly. Their reflectiveness, stoical resilience, systematic efforts, and meticulous approach are clearly advantageous when these features are adaptively needed. The disadvantages reflect an uninquiring attitude, lack of enthusiasm, and tolerance of monotony, potentially leading to prosaic routinization of activities.

Reward Dependence - Attachment, Social Attachment
Reward Dependence reflects a heritable bias in the maintenance of behavior in response to cues of social reward. It is observed as sentimentality, social sensitivity, attachment, and dependence on approval by others. Individuals high in Reward Dependence are tender-hearted, sensitive, socially dependent, and sociable. One of the major adaptive advantages of high Reward Dependence is the sensitivity to social cues which facilitates affectionate social relations and genuine care for others. The disadvantage is related to suggestibility and loss of objectivity frequently encountered with people who are excessively socially dependent.

Individuals low in Reward Dependence are practical, tough-minded, cold, socially insensitive, irresolute, and indifferent if alone. The advantages of low Reward Dependence are personal independence and objectivity not biased by efforts to please others. Its adaptive disadvantage is related to social withdrawal, detachment, and coldness in social attitudes.

Persistence - Ambition, Partial Reinforcement
Persistence reflects a heritable bias in the maintenance of behavior despite frustration, fatigue, and intermittent reinforcement. It is observed as industriousness, determination, and perfectionism. Highly Persistent people are hard-working, perseverant, and ambitious overachievers who tend to intensify their effort in response to anticipated reward and perceive frustration and fatigue as a personal challenge. High Persistence is an adaptive behavioral strategy when rewards are intermittent but contingencies remain stable. When the contingencies change rapidly, perseveration becomes maladaptive. Individuals low in Persistence are indolent, inactive, unstable, erratic; they tend to give up easily when faced with frustration, rarely strive for higher accomplishments, and manifest a low level of perseverance even in response to intermittent reward. Accordingly low Persistence is an adaptive strategy when reward contingencies change rapidly and may be maladaptive when rewards are infrequent but occur in the long run. Also, Persistence can be objectively measured by the partial reinforcement extinction effect (PREE) in which persistent individuals are more resistant to the extinction of previously intermittently rewarded behavior that other individuals who have been continuously reinforced.

Self-Directedness quantifies the extent to which an individual is responsible, reliable, resourceful, goal-oriented, and self-confident. The most advantageous summary feature of self-directed individuals is that they are realistic and effective, i.e., they are able to adapt their behavior in accord with individually chosen, voluntary goals based on a realistic assessment of facts. Individuals low in Self-Directedness are blaming, helpless, irresponsible, unreliable, reactive, and unable to define, set and pursue meaningful internal goals. Such poor resourcefulness and unrealistic behavior are often disadvantageous to the individual.

Cooperativeness quantifies the extent to which individuals conceive themselves as integral parts of human society. Highly cooperative persons are described as empathic, tolerant, compassionate, supportive and principled. These features are advantageous in teamwork and social groups, but not for individuals who prefer to live in a solitary manner. Low Cooperativeness involves self-absorbed, intolerant, critical, unhelpful, revengeful, and opportunistic behavior in persons who primarily look out for themselves and tend to be inconsiderate of other people’s rights or feelings.

Self-Transcendence quantifies the extent to which individuals conceive themselves as integral parts of the universe as a whole. Self-transcendent individuals are spiritual, unpretentious, humble, and fulfilled. These traits are adaptively advantageous when people are confronted with suffering, illness, or death, which is inevitable with advancing age. They are disadvantageous in most modern societies where idealism, modesty, and meditative search for meaning might interfere with the acquisition of wealth and power. People who are low in Self-Transcendence are described as practical, self-conscious, materialistic, and controlling. Such individuals are expected to be well adapted in most Western societies because of their rational objectivity and materialistic success. However, they consistently have difficulty accepting suffering, loss of control, personal and material losses, and death, which lead to adjustment problems particularly with advancing age.