As an effective tool in Demand-Side Response (DSR) programmes, the 'Time-Of-Use' (TOU) tariff stimulates customers to modify their usage behaviour. However, there are considerable deviations in responsiveness among different customers, even to the same TOU tariff. There are two drawbacks in the existing analyses: 1) customers' psychological features are omitted, i.e. the willingness to respond; 2) the interaction effect among features, which describe the load and socio-economic characteristics, are ignored. Therefore, this paper proposes an interaction-aware framework to identify the significant psychological, socio-economic and load criteria to evaluate customers' responsiveness to different TOU tariffs. The results find that the significant characteristics of the more responsive customers include: smooth load profiles, high consumption levels overnight, large family size. A significant psychological feature interacted with load features demonstrates that customers with lower confidence in load-reduction activities also can successfully respond, as long as their load consumption is small.