Final answer:
The Davis-Moore thesis argues that social stratification is necessary for society and implies that upward social mobility is possible across generations.
Step-by-step explanation:
The Davis-Moore thesis, developed by sociologists Kingsley Davis and Wilbert E. Moore, states that social stratification is necessary for the functioning of society. According to their theory, certain highly skilled positions require more education and qualifications, and therefore, should be rewarded with higher pay and status. This implies that upward social mobility is possible across generations.