To normalize or not to normalize for few distinct values

Question

Assuming in a Postgres database, you have a table called party, which can have less than 5 well-defined party_types such as 'Person' or 'Organization'.

Would you store the party_type in the party table (e.g. party_type = 'Person') or normalize it (e.g. party.party_type = 1 and party_type(id, name) = (1, 'Person'))?
And why?