Variations in geographical environment have influenced the life style of the people in the country who differ ethnically, too. The contrasts may be seen in the hill people of the north east, the inhabitants of the Northern plains and those of the coastal areas. Besides, there is a large number of tribes inhabiting the hilly and forested areas of the country. All these people have their distinctive ways of living, customs and traditions. The great cultural diversity in India stems from her ancient and rich past. Groups of people belonging to different races, tribes, religion and culture continued to settle in India during the past many centuries. The local inhabitants absorbed their traditions and cultures. Due to assimilation of various cultures, there grew a composite culture in India. 
             India possesses a variety of people who belong to different ethnic groups and have different physical traits. The people of South India have essentially Dravidian traits. They are supposed to be the original inhabitants of India who were little affected by the invading groups of the North. It must be remembered here that the Vindhyan range formed a formidable barrier between the north and the south, the latter being impregnable due to rough terrain and thick forests. The inhabitants of the north and north east too have retained their distinctive racial features because of less intermixture with other people. The people of the Indo-Gangetic plains and western India, on the other hand, exhibit a mixture of several traits due to their continued mixing with the people of different races.
           The diversity runs through religions, languages, social customs, cultural and sub-cultural beliefs, political philosophies and ideologies too. Though there is no State religion in India, yet the State guarantees the freedom of following and practising all religious faiths. Among the ma jor religions are, Hinduism (practised by 82-6% population), Islam (practised by 11-35% nopulation of the country), Christianity (practised by 2-43% population), Sikhism (practised by 1-96% population), Buddhin (practised by 0-71% opulation), Jainism (practised by 0-48% population) and others (practised by 0-3% population). 
            As far as diversity in languages is concerned, the Constitution recognizes eighteen major languages, but as many as 1,652 languages and dialects are noken in India. Broadly, these languages belong to three families : (1) Indo- van (2) Dravidian and (3) European. Hindi is the official language of India and English is an associate language. Hindi is spoken by the highest number af people, followed by Telugu, Bengali, Marathi, Tamil, Urdu, Gujarati, Malayalam, Kannada Oriya, Bhojpuri and Bengali in the descending order. 
             The total tribal population in India represents 7-8% of the country's total population. The Santhals, Bhils, Meenas, Gonds, Mundas, Nagas, Khasis, Oraons, Garos, Hos, etc. are the major tribes of India. There are five states in India where tribes constitute 70 to 95% of the total population of the state. These states are Mizoram, Nagaland, Meghalaya, Arunachal Pradesh and Tripura. Madhya Pradesh followed by Orissa, Bihar, Gujarat and Maharashtra possess two-thirds of the total tribal population in India.
          Racially speaking, according to Guha Indian population is derived from six ethnic groups viz. (1) Negritos, (2) Proto-Australoid, (3) Mongoloid, (4) Mediterranean or Dravidian, (5) Brachy Cephals and (6) Nordic Aryans. The Negritos are the oldest people of Africa who came to India. They are found among the tribes of south India and Andman Island and have retained their language and culture. Proto-Australoids are spread all over the country. These people laid the foundation of Indian civilization. The Kol and Munda speaking people are survivors of this group. The Mediterranean or the Dravidians are reputed to have buiit-up the Indus valley civilization. Later, they spread to whole of India. The Mongoloids are confined to the north- eastern parts of India. Nordic Aryans were the last to come to India from Central Asia, between 2000-1500 B. C. and settled in Punjab from where they spread to the Gangetic valley. These people encountered the highly civilized Indus valley people. 
            Running through various diversities is the thread of basic unity which makes India a great nation. According to Srinivas, the unity of India is essentially a religious one. People may worship different deities but the religious scriptures-Vedas, Puranas, Brahamanas and Epics knit the hetero- geneous groups together into one religious socicty. All believe in the doctrines of "Karma". "Dharma", rebirth, immortality of soul, renunciation and Moksha. People following different religions may visit different places of pilgrimage, but all have a common goal of earning religious merit by visiting a sacred place. For example, a Hindu visits Badrinath, Kedarnath, Amarnath, Varanasi etc.. a Buddhist visits Kushinagar, Sarnath, etc., a Jain visits Pawapuri, Shravanbelgola, Osiya, etc. while a Muslim visits Macca and Medina. All of them are guided by the same desire of earning religious merit.
           Thus, in spite of several diversities of physical environment and culture. There prevails an underlying unity which binds people of the nation together. A person may be a Punjabi, a Maharashtrian, a Gujarati, an Oriya, a Bengali, a Bihari, an Assamese, a Tamil or a Keralile, but above all, he is an Indian. It is so because all of them have fought for Independence. All of them stood as one nation during the Post-Independence Chinese aggression and the Pakistani aggressions. All of them are actively participating in national development. It is the spirit of oneness that binds the whole country together and leads it to the path of progress and development. Last, but not the least, our economic, social and political philosophies are broadly based on equality, justice, liberty, rationality and secularism. Our laws apply to all people without any discrimination. Our Constitution provides guarantee to all people alike. The planning aims at the uplift of all types of weaker sections of society. The common customs and consensus in social values have preserved our traditional culture. The above points clearly establish that there are many physiographical and cultural diversities in India but practically they have an inherent element of unity and thus we can say, with pride, that India is a land of 'unity in diversity'.