Peep Laja of Conversion XL has really done his homework.

In this truly educative article on the science behind writing the most effective copy, he presents a comprehensive review of the key work of the most prominent thinkers in the art and language of persuasion.

He starts by citing the six principles of persuasion from Dr Robert B. Cialdini, who wrote back in the 80s about the pyschology behind persuasion, and whose theories still remain pertinent in today's world of online content.  

Thus, you will see remarkable and effective writing in the present day reflecting Cialdini's recognition of the importance of reciprocity - that people will respond more kindly when they feel something is being given openly to them (educate first, sell later). You will note also that Cialdini's belief that [social] proof is key (i.e. that "people decide what’s appropriate for them to do in a situation by examining and following what others are doing") continues to chime with what we know of how buyers research/compare when making purchasing decisions nowadays.

Delving deeper, Laja looks next at the work of Professor Gifford of the University of Victoria who co-authored a report analysing how influential messaging was around the subject of climate change. Gifford's work proposes five key ingredients for the most efficacious messages, comprising urgency, targetting, integrity, positivity and validity.

And in this same vain, the work of the Heath brothers is summarised. A business school professor at Stanford and an educational consultant at Duke, Chip and Dan Heath have researched what it takes to make ideas really resonate and "stick" with an audience. Again, six core elements are highlighted to ensure success, ranging from simplicity to great story-telling, from credibility to creating an emotional connection. 

There is a wealth of compelling expertise and scientific knowledge here that can't fail to persuade you to re-think your copywriting.