Are studies published in conference proceedings well-regarded in social sciences fields (e.g., psychology)? First, a bit of context. I have a BA in psychology and an MSc in an interdisciplinary field (educational sciences/learning analytics) that is a combination of psychology, educational sciences and computer sciences. I am completing a PhD in this same interdisciplinary field with a research group that is technically under the Engineering and Computer Science faculty of our university. My supervisor and all my colleagues have degrees in psychology (i.e., none of us are computer scientists). 

I am about to finish a cumulative dissertation made up of: 


a literature review published in a high impact factor journal 
an extension of the literature review published in the proceedings of the annual conference in our community.
a quasi-experiment that will be published in the proceedings of the annual conference in our community. 


The international research community in rather small (about 300-400 people attend the annual conference). The acceptance rate to the annual conference is quite low (average 30% of 400 full paper submissions are accepted). I quite like that it's small and interdisciplinary, but it does raise a few questions as to what constitutes a proper publication. I have plenty of colleagues who consider themselves computer scientists and they consider conference proceedings to be publications. However, my psychologist colleagues tell me that journal articles are still much better than conference proceedings. 

Does anyone have any insight on how well-regarded conference proceedings are in social sciences? More specifically, should I be worried about hurting my chances of getting a postdoc position in psychology-leaning research groups because I don't have any experiments published in an academic journal?
I have worked at the intersection of psychology, educational sciences and computer sciences and there was always friction between the computer scientists who wanted to publish in conferences and the non-computer scientists who wanted to publish in journals. I think most psychologists who deal with computer scientists know about the conference culture, and most computer scientists that deal with psychologists know about the journal culture. That said, I believe, it is much easier for a computer scientist to get an idea about how competitive a journal is compared to a psychologist trying to understand how competitive a conference proceeding is. 

If your plan is to stay in Psychology and you have the choice about conference or journal publications, then all things being equal, go with journal publications. If you want to go to the conference or you are getting pressure to publish in conference proceedings, then it is no big deal, although, there are even differences between conference proceedings and journals in computer science so you probably want to prove you can write/publish a full article.