Elementals Personality

that each is caused by a surfeit of one of the four classical elements in the body — air produces extroversion and cheerfulness, fire produces passion, determination and a short temper, earth produces analytical, dogmatic and depressive personalities, and water produces calm, flexibility and passivity.
While variation can occur in different cases, most elements are associated with specific personality types:
Air is vivacious, flighty and prone to change. Air-themed characters are often mercurial, prone to being pulled hither and yon by passing fancies and interests. They may be depicted as lively, talkative, and gregarious people, or else as all-but-literal airheads unable or unwilling to concentrate on important matters. Alternatively, air is sometimes associated with pacifism, non-aggression, and diplomacy.
Darkness is reclusive, secretive and amoral. Good characters associated with darkness are usually brooding, pragmatic and solitary, concealing their good hearts beneath layers of metaphorical shadows. Evil darkness users tend to be schemers and manipulators, and may be outright inhuman in mentality.
Earth is typically portrayed as calm, stable and enduring. Positive earth-aligned characters are often reliable, patient and unlikely to let their emotions get the best of them. More negative portrayals can have them as reactionary, stuck in their ways, and difficult to motivate.
Electricity is active, filled with energy, and often a little loopy. On the one hand, characters associated with this element may be vivacious, energetic and unwilling to sit idle when there's work to be done. On the other, they may also be annoying and difficult to keep up with when they aren't simply a Psycho Electro. Sometimes juxtaposed with fire.
Fire is associated with passion and emotion. Fiery characters and beings can be found almost everywhere on the emotional spectrum, as long as whatever they feel is felt strongly. They are also prone to rocketing to extremes of feeling on a dime, and are often Mood Swingers. More positive portrayals make such characters vivacious, passionate and genuine in their expressions. More negative ones are prone to being violent, unstable, and difficult to deal with or predict — and heaven help you if they're also a Pyromaniac. When paired with Elemental Hair Colors, this often results in Fiery Redheads. This is often associated with Fire Is Masculine.

Ice is often associated with a lack or dampening of emotions. Sympathetic ice-aligned characters, much like their earthen counterparts, may be depicted as rational sorts who don't let emotion and bias cloud their judgements, and are often keenly intelligent. More negative portrayals have them as unfeeling, cold and cruel. Often contrasted with fire's emotional nature, as in Fire/Ice Duo.
Light is usually upright and moralistic. Good light-themed characters are usually wise, innocent, or relentlessly cheerful, but always very morally focused. Evil ones are usually prideful, arrogant, and judgmental. Frequently contrasted with darkness, sometimes with fire.
Metal is often similar to earth and ice in being associated with stubbornness and restrained emotions, as well as having literal iron willpower. More than being calm, however, metal is more likely to be simply emotionless. On the one hand, this may lead metal-wielding characters to be rational and reflective; on the other, they may just as easily be robotic, inflexible and passionless.
Water is yielding and adaptable. The adaptable aspect of water can also be depicted as mercurial, with such characters being Mood Swingers, with a heavier focus on moody and somber moods in contrast to fire's tempestuous passions. Mirroring their element's ability to take on the shape of the vessels it is given, water-aligned characters are often diplomatic and adaptable, and willing to put their own passions aside for the sake of greater causes. Such characters can often be the glue holding all the other emotional extremes together, or they may simply be spineless and with little moral fiber. Often associated with women and contrasted with fire.
Wood is caring, calm, and nurturing due to being associated with growth and with a very passive form of life. Plant-wielding characters are typically benevolent sorts, and often healers. On the other hand, pacifism and meekness easily become cowardice in excess.
Some works posit direct causal relationships between powers and temperaments, instead of these simply happening to occur together. In most such cases, specific emotional states are necessary to fully harness and control an associated element. As such, a pyrokineticist might need to work themselves up into a rage to stoke their flames to their greatest strength, while a cryokineticist might instead need to enter a state of dispassionate calm to properly control ice.