What is the difference between social identity and self-identity?

a. social identity is a static concept, whereas self-identity is dynamic.
b. social identity focuses on similarities among people, whereas self-identity focuses on individual differences.
c. social identity describes postindustrial identities, whereas self-identity describes postmodernist identities.
d. social identity is a sociological concept, whereas self-identity is a psychological concept.
e. none of the above; there is no difference between the two concepts.

b)

Explanation:

First, let's look at the definition of both concepts:

We can tell that social identity focuses on similarities among people belonging to groups, while self-identity refers to what makes us different to other people.

However we're going to explore why the other options are not true:

a) Social identity is a static concept, whereas self-identity is dynamic: This is false, both concepts are dynamic since we can change our belonging to a group as well as our perception of ourselves can change if we change our hobbies or goals, for example.

b) Social identity focuses on similarities among people, whereas self-identity focuses on individual differences: This is true, social identity makes us part of one group because we are similar to their members whereas self-identity focuses on our own characteristics, which are what make us different from other people.

c) Social identity describes postindustrial identities, whereas self-identity describes postmodernist identities: This is false. Post industrial identities refers to the concept of self pride related to nationalism, and while belonging to a country is part of social identity is not all of it. The same way, postmodernism focus in how there are many truths and stories we can tell about ourselves and our past based on how we experimented but this doesn't really have to do with identity.

d) Social identity is a sociological concept, whereas self-identity is a psychological concept: False. Social identity has to do with society but both are psychological concepts.

e) None of the above; there is no difference between the two concepts: This is clearly not true.

Thus, the correct answer is b.