Table 4 Possible important implications of the findings from this survey

‘Benefits arguments’ were initially convincing. However, most respondents recognized that there is a missing premise: a reason needs to be given to justify respecting human interests in avoiding suffering differently from NHA similar interests in avoiding suffering [12].

HCWs’ support for AR may not be based on cogent philosophical rationales, and rather may be based on group membership effects, with commitment to a current ‘Kuhnian’ scientific research paradigm of AR [23]

Most were not convinced by ‘human exceptionalism arguments’, despite these being the main pro-AR arguments in the literature [12]-[15]

Common counterarguments in the philosophy literature explain this well:

a) the ‘argument from species overlap’ [sometimes called the ‘argument from marginal cases’], [18]-[20]

b) suggestions that NHAs may be ‘subjects-of-a-life’ [i.e. experiencing subjects of their own life] and ‘sentient’ [21],[22], and

c) suggestions that species membership may not be morally relevant [‘speciesism’ arguments that draw a parallel to previous prejudices such as racism and sexism, where like-interests in one group are disregarded compared to another group] [22].

Almost none thought that NHAs should be considered property, or that NHAs are not sentient. Importantly, legal protections for NHAs are based on the assertion that these NHAs are property [24], and belief that NHAs are sentient is the basis for the counterarguments that question the moral permissibility of AR.

Current AR animal protection practices may not be in line with HCWs’ beliefs about NHAs.

Most respondents were supportive of AR even after considering the arguments and counterarguments given.

Social science research is needed to determine why philosophical argumentation does not translate into practical behavior change [25].

Counterarguments suggesting that “researchers have not looked hard enough for alternatives to animal experimentation” and “if more effort was devoted to developing alternative research methods that do not use animals, animal experimentation may not be necessary anymore” were convincing for most respondents. Thus, some of the support for AR is based on the belief that there are no alternative research methods.

Focus on the return on investment from AR and alternative research methods may help people in considering the ethics of AR [26],[27] The translation rates into human benefit (i.e. accuracy of research models) should be determined for both AR and alternative research methods in order to inform the debate about AR.