Hall et al. (2020) brought the well-known distinction between reflexive system and automatic system to the forefront when they wondered which of the two cognitive systems dominated in the response processes to the COVID-19 emergency. However, it is probably impossible to answer this question, although it highlights the actual need to explore what works in emergency response processes, apart from the structural and organisational factors that were explained in the previous chapter. The scientific community is divided on the matter. On the one hand, the literature on emergency management is still dominated by the hyper-rational planning approach, which presumes a clear prevalence of the reflexive system in emergency response processes. On the other hand, several policy analysts believe that response processes to crises and disasters are able to proceed in part thanks to mental and behavioural mechanisms pertaining to the automatic system, (Boin and ‘t Hart 2007; Arendt and Alesh 2015; Ansell and Boin 2019; Ravazzi 2023). Among these scholars, some have gone as far as to claim that improvisation plays a key role in emergency response processes (Turner 1994b; Mendonça et al. 2001; Mendonça and Wallace 2004; Webb 2004; Kendra and Wachtendorf 2006; Webb and Chevreau 2006; Kapucu 2008; Ansell et al. 2010; Eriksson and McConnell 2011; McConnell 2011; Schulman and Roe 2011; McEntire et al. 2013; Boin and van Eeten 2016; Sylves 2020; Roud 2021). According to Webb and Chevreau (2006, p. 67), ‘successful responses to crises occur not in spite of but because of various unscripted activities, improvised behaviour, and emergent organisational structures’. When describing the intergovernmental relationships of the US emergency management system, Sylves (2020, p. 251) considered improvisation as ‘part of the ethos of the system’. The empirical literature on emergency responses offers evidence that supports this hypothesis. According to Boin and Van Eeten (2016), the already mentioned CAISO team, which is responsible for the management of the California electric grid, managed to avoid the collapse of the system during the 2001 crisis by combining ‘a rapid decentralisation of actions and improvisation’ (131). Likewise, the coordinated actions that the healthcare delivery system of Ontario (Canada) put in place in 2003 to respond to the SARS epidemic seem to have benefitted from a good deal of improvisation (Varley 2009a). Soujaa et al. (2021), who analysed the rapid emergency responses in Texas against the 2015 Ebola infection, discovered that the emergency managers often deviated from the emergency plans and improvised. Again, according to Oscarsson and Danielsson (2018) and Oscarsson (2022, 732), the personnel who managed the 2015 refugee emergency in Sweden put ‘a lot of improvisation and prioritisation’ into action.