Schwartz built on the research of a social psychologist called Milton Rokeach, who had been carrying out research into values since the 1960s. This body of literature is now well-established and robust. Schwartz’s model has been used in thousands of subsequent academic papers (the original article alone has been cited over 3,700 times). Hundreds of papers – amounting to literally 100,000s of participants – have also tested the relationships between the values, using different lab and field methodologies across over 80 countries and in 48 different languages, the vast majority of these papers confirming the relationships Schwartz outlines.
In addition to asking people what they valued, researchers have verified the relationships between values using peoples’ friends’, partners’ and families’ perceptions of their values; [ref]Bardi, A. and Schwartz, S.H. (2003). Values and behavior: Strength and structure of relations. Personality and Social Psychology Bulletin, 29 (10), 1207-1220.[/ref] and tests to see how easily a value-relevant word is recalled from memory.[ref] Maio, G.R. (2010). Mental Representations of Social Values. In M.P. Zanna, ed. Advances in Experimental Social Psychology, Vol. 42. Burlington: Academic Press, 2010, pp. 1–43.[/ref] They have also tested the validity of the model using correlations between behaviours associated with the value sets, such as observing that prioritising tradition and conformity tend to result in similar behavioural tendencies, have some overlap with highly security-driven individuals, and very little overlap with highly stimulation-driven individuals.[ref]Bardi, A. and Schwartz, S.H. (2003). Values and behavior: Strength and structure of relations. Personality and Social Psychology Bulletin, 29 (10), 1207-1220.[/ref]
The model is also the basis of the values component of the European Social Survey, the largest trans-European social survey, involving almost every national academic funding body in Europe, and collecting data from around 30 countries every two years. The World Values Survey, ‘the world’s most comprehensive investigation of political and sociocultural change’ also draws on the Schwartz model.
In short, it’s pretty robust. That’s not to say it is a complete theory of human motivation – rather, it’s an approximate but well-founded model of how human values relate to each other, with measurable impacts on our attitudes and behaviours.