Caffeine improves memory, sociability, and alertness. Cocaine increases alertness, feelings of well-being, euphoria, energy, competence, sociability, and sexuality. In many cultures, elephants represent strength, power, wisdom, longevity, stamina, leadership, sociability, nurturance and loyalty. Studies have also indicated individual variation in temperament, such as sociability or impulsiveness. This model measures levels of emotionality, activity, sociability, and shyness in children. For example, the hormone testosterone is important for sociability, affectivity, aggressiveness, and sexuality. Cross-cultural research has shown gender differences on the tests measuring sociability and emotionality. High levels of norepinephrine leads to anxiety-proneness, dependency, and high sociability. Among humans, smiling is an expression denoting pleasure, sociability, happiness, joy or amusement. Phenibut is used recreationally due to its ability to produce euphoria, anxiolysis, and increased sociability. It is commonly used in social settings due to its capacity to enhance sociability. Issues such as soothability, rhythmicity, sociability, and arousal make up this construct. The network society is also manifested in the transformation of sociability. Lavoisier had a vision of public education having roots in "scientific sociability" and philanthropy. Such forms would include "subordination", "superordination", "exchange", "conflict" and "sociability".