According to the law of nature all human beings are not the same. There are marked differences amongst human beings which in turn has generated various social groups in the society who discriminate amongst themselves. This leads to the development of inequality in the society.
However it has been observed that although some differences lead to the development of inequality, others do not. They linger on in the society as differences but people are in no way differentiated on that basis. For instance the caste system during the early Vedic period, was merely a difference as people could choose their occupation, according to which they were designated a class. But from the Later Vedic period the caste system became rigid, because people were designated castes according to their birth. They were soon immensely discriminated on this basis. This led to the development of inequality in the society.
In the contemporary world, social inequalities in society usually arise due to differences in gender, age, class, ethnicity structural factors, (such as geographical location, citizenship etc.) People are often discriminated on this basis with regard to access to a variety of rights in the society, such as facilities available, political representation, participation etc.
Various studies have revealed that socio-economic and political differences often lead to inequalities. For instance, high death rates and stress-related diseases often are a repercussion of unequal distribution of wealth in the sphere of income. Similarly, democratic institutions in a society may cease to work effectively due to deepening inequalities, which may lead to the development of social conflict as well as political instability and may in turn lead to the establishment of authoritarian regimes.
It has been observed that the patterns of inequality have changed in the post cold-war era, [after-1991] as Eastern European countries have shifted from state controlled to market-based economies. Therefore the nature of social inequalities in the post-socialist regime has undergone a variety of significant changes. For example, although it has been relatively stable in the western-most countries, it rose significantly in many countries emerging from the former Soviet Union. These countries have ever since witnessed extreme poverty. This clearly indicates that inequality amongst various social groups has been developing in different ways across the world.