It’s very easy to have biases against people. It’s very easy to think that a person is not worth saying hi to because they don’t wear interesting enough clothes or come from small towns. It is very natural to not want to sit next to people who are not good looking or not popular. Similarly, it is easy for people of a particular caste or religion consider people of a different caste or religion inferior.
Humans have this natural tendency because of evolutionary psychology. Our brains are wired to have these biases or discriminate because of the need for being protected. Protectionism is what makes us stereotype certain groups and consider them dangerous, or unworthy. In ancient times, like in the state of nature, humans needed to protect their scarce resources from acquisition by other tribes and therefore discriminated against other tribes.
However, in the modern world, where systems recognize meritocracy, equal opportunity, irrespective of caste/class/society, the instinct to discriminate hasn’t left us. We don’t really need it, unless our life is being threatened, but we still use it a lot. And therefore racism, sexism, casteism, and all kinds of discrimination are still prevalent.
To come above the natural urge to discriminate on these superficial parameters is the challenge. That’s where “becoming bigger” or maturity comes in. Values like unconditional compassion, empathy, acceptance and altruism enter the picture.
Hence, it is absolutely accurate to assume that those people who recognize that everyone is equal, and that at the end of the day we’re all humans, irrespective of national/racial/gender identities, are in fact more mature. If they can at least begin to come above their natural instinct to view another as different, then they are clearly more evolved. And that is why it is no surprise that such people, who believe in equality and are called liberals, are also considered to be the intellectuals in most societies.