Due to the impetus of climate change and the consequential need to conserve energy, the adaptive comfort model has gradually become a popular focus of thermal comfort research, representing one of the most sweeping changes across the field in the past few decades. However, the mechanism behind the adaptive model, especially with regard to certain key hypotheses, still requires further clarification. To offer more solid support for the hypothesis that people with greater personal control tend to accept wider ranges of indoor thermal environments, we designed an investigational study in which occupants in residential apartments had different degrees of personal control over their space heating systems. Through statistical analysis of the thermal responses of each group, considerable differences in thermal comfort were observed, although occupants in the experimental groups experienced quite similar comfort-related thermal parameters. The results show that occupants with personal control had 2.6 degrees C lower neutral T-op and expressed lower expectation to change their current thermal conditions than those without the capability of personal control. These findings provide support for the adaptive model and can serve as a valuable reference for the design of more efficient space heating systems. 2014 Elsevier B.V. All rights reserved.