Final answer:
John and Dan differ on one of the factors of the Five-Factor Model, which include openness, conscientiousness, extroversion, agreeableness, and neuroticism. These factors describe personality traits on a spectrum and are stable over one's lifespan but can change slightly with age.
Step-by-step explanation:
Differences in the Five-Factor Model
The Five-Factor Model, also known as the Big Five personality factors, includes openness, conscientiousness, extroversion, agreeableness, and neuroticism. Every individual exhibits these factors to varying degrees along a spectrum. Openness describes creativity versus practicality, conscientiousness covers organizational skills and diligence, extroversion reflects sociability, agreeableness encapsulates traits like trustworthiness and kindness, and neuroticism indicates emotional stability. It is important to understand that these factors are relatively stable throughout one's life but can exhibit slight increases or decreases with age, and they have been found to be universal across cultures and ethnicities.
If John and Dan exhibit differences in one of these factors, they would vary in how they score or express that particular trait. For example, if they differed on conscientiousness, John might be very organized and reliable whereas Dan could be more spontaneous and flexible.