In many ways Leos are the children of the zodiac. Fun, adventurous, genuine, generous and highly charismatic they like to be larger than life and enjoy showing off, being admired, praised and appreciated. Very playful and competitive they like to be the best in whatever they do. Outwardly their egos tend to appear to be immune to criticism, while inwardly they are sensitive to criticism from those they respect or care about.
Outgoing
Charismatic
Sociable
Extrovert
Self confident
Optimistic
Generous
Self motivated
Natural leaders
Genuine
Enthusiastic
Passionate
Adventurous
Direct
Ambitious
Spontaneous
Independent
Courageous
Straightforward
Determined
Deep thinking
Persistent
Willful
Independent
dramatic (good and bad!)
Forgiving (rarely hold a grudge)
It's worth noting that most good Leo traits and characteristics have an equal and opposite bad trait or characteristic. For example, someone who is highly analytical could be described as either intelligent (good) or unemotional (bad). Someone who is spontaneous (good) is also impulsive (bad).
Creating drama and excitement if they get bored
Domineering
Egotistical
Self absorbed
Aggressive
Confrontational
Melodramatic
bored easily
Impulsive
Impatient
Reckless
Blunt spoken
Stubborn
Opinionated
Inflexible
Pretentious
Vain
Praise and flattery
Risks
Excitement
Living for the moment
Romance to be fun and exciting
Quality
Luxury
Showing off
Criticism
Boredom / indifference
Taking instructions
Being second place
One of the fascinating things about astrology is the patterns which exist. Leo personality traits certainly aren't random. They come from a combination of the signs ruling planet, element, polarity, house and quality. All of these are also used (consistently) elsewhere within astrology and come together to form the unique package which is the Leo personality.
No. The above traits exist if someone has a Leo sun sign. However every individual also has other planet placements (Moon, Mars, Venus etc) which modify this behavior. In some cases one or more of the basic personality traits listed above will be modified or even replaced. Only by examining all the planet placements for an individual can we get a complete picture of their unique personality. A skilled astrologer can often calculate these backwards from the ways that the basic sun sign behavior is being modified.
As children we are subjected to many experiences and influences. These can lead to a determined effort to modify our personality and behavior. The traits still exist, but they can be over ridden by free thought. It's fairly common for negative traits to gradually diminish as a person gets older, wiser and more socially adept.