functional programming is a style of programming :

• using mainly expressions over statements.
• The basic building block is the function. Functions are mainly side effects free.
• Iteration is done using recursion and not loop.
• Immutable data structures like lists and graph are priviledged over mutable data structurex like array or matrix.
• States are expressed explicitly in data and handled through stateless code.

Functional paradigm is a very different way of thinking programming. So the learning curve is quite hard at the beginning. The consequence is some social elitism. For a learning purpose, the challenge is worth the reward.

Multicultural people are usually more open minded, as knowing multiple paradigms will make your more efficient. So Object Oriented Programming skills plus Functional programming is a good thing.