 His work in the areas of evolutionary theory and comparative anatomy has appeared in such publications as "Psychological Reports",
"Acta Biotheoretica", the "British Medical Journal", and the "Annals of Human Biology".As a political philosopher Verhulst writes on direct democracy, alternative money systems, freedom of speech, secession from the European Union, homeschooling and other subjects.He is also engaged in networks promoting direct democracy such as the Belgian-Dutch (Flemish) "Werkgroep Implementatie Tijdsgeest" (WIT), Democratie.Nu, Referendum Platform, and the European Democracy International group.