BackgroundDuring the first wave of the COVID-19 pandemic, social distancing and hand hygiene have been the primary means of reducing transmission in the absence of effective treatments or vaccines, but understanding of their determinants is limited. This study aimed to investigate knowledge and socio-cognitive perceptions, and their associations with such protective behaviours, in UK university students. MethodsA cross-sectional online survey of 293 students was undertaken on 13 May 2020. Survey questions addressed demographics, knowledge of the disease and effectiveness of the protective measures, risk perception, socio-cognitive perceptions (e.g. attitude, social support, and self-efficacy), habit, time factors and trust, as well as the hand hygiene and social distancing behaviours. Multiple linear regression was used to identify the strongest associations of potential determinants with behaviour.ResultsParticipants reported high levels of social distancing with 88.9 % answering “Mostly” or “Always” for every activity, but only 42.0% reporting the same for all hand hygiene activities. Knowledge of the effectiveness of each activity in preventing transmission was high, with 90.7% and 93.5% respectively identifying at least 7 of 8 hand hygiene or 9 of 10 social distancing activities correctly. Habit (β = 0.39, p <0.001) and time factors (β = 0.28, p <0.001) were the greatest contributors to unique variance in hand hygiene behaviour, followed by ethnicity (β = -0.13, p =0.014) and risk perception (β = 0.13, p = 0.016). For social distancing behaviour, the determinants were self-efficacy (β = 0.25, p <0.001), perceived advantages (β = 0.15, p = 0.022), trust in policy (β = 0.14, p = 0.026) and gender (β = -0.14, p = 0.016). Regression models explained 40% hand hygiene and 25% social distancing variance.ConclusionsThis study indicated that communications about effectiveness of hand hygiene and social distancing behaviours had been effective in terms of knowledge acquisition. However, in the light of likely second waves of COVID-19, attention to maintaining social distancing behaviour and improving hand hygiene behaviour may need to address more difficult areas of changing habits, overcoming time factors and building trust, as well as interventions to increase self-efficacy and address risk perception concerns.