Yes, non-tech people can be testers

[ Why You Should Consider Non-IT Professionals for QA Roles | Posted on 10/08/2012 | http://blog.utest.com by Jamie Saine ]

Combining traditional QA practices with non-traditional players helps companies test products from all angles. …
 Two attributes are critical for good testers regardless of academic background, which non-IT persons can develop and receive training, they pointed out. … The first is domain knowledge, …  the tester must also understand the SDLC processes or models for the app as used by their employer, such as agile, iterative or waterfall, they said.

[ Software testing is a skill of many skills – Jesper Ottosen on the EuroStar blog ]

Business skills or domain know-how … Application skills or technical know-how … software testing itself and the skill of software testing tools … Project management or task coordination know-how … Notice that the above skill areas are very “hard” skills as compared to “soft” or personal skills. All kinds soft skills come into play in software testing for me to single out anyone. Some situations you have to be flexible, others stern. Some situations require results orientation and some situations require attention to all details. I can see the skills of all personality in play in software testing – as software testing is a skill of many skills.

[ Testing AND Checking]:

You apply both your left and right side of the brain – you check and test – you do tasks and seek value – you apply routinized and bespoke activities. You can use the distinction to guide you to a context-driven testing approach.