Differences Between PDA and Non-PDA Autism


A Demonstration of Differences Between PDA and Non-PDA Autism, a transcript of a presentation by Sally Cat at The Autism Show at ExCeL London on 15th June 2019

Sally's introduction explains:

"Hello, I’m Sally Cat I am a PDAer

This means my neurology fits the Pathological Demand Avoidance profile, which is currently classed as an Autism Spectrum Condition. PDA is much more than the eponymous demand avoidance. The data I'm presenting is from a large study I ran in 2016 which compares the ranking of 155 potential distinct PDA traits between PDA and non-PDA autistic respondents. These 155 traits were whittled down from a preliminary 228 suggested by members of the adult PDA community via a preliminary in-group study.

My role was coordinator, rather than leader (more PDA-friendly, as we none of us like to be led). I am not a trained researcher. My interest was, and is, bottom up: a member of the adult PDA community seeking answers in the face of academic ignorance towards adult PDA. Being an enthusiastic amateur (and pathologically avoidant) I did not seek ethical approval for the study.

What I did achieve was to galvanise 90 non-PDA autistics and a whopping 290 PDA adults to participate. I should point out that nearly 100% of these PDAers were (and still are) self-diagnosed. This is because gaining adult PDA diagnoses is almost as impossible as kissing one’s own elbow. Please, though, do not assume that we self-diagnosed PDA adults have applied the PDA label to ourselves without self-reflection or thought. The fellow PDA adults I have come to know via Facebook are the most soul-searching group I have ever had the good fortune to meet.

The resulting spreadsheet was so daunting to me that I sat on it for three years incapacitated by demand avoidance-generated dread. Happily, Nottingham University Forensic Psychology PhD student, Grace Trundle, kindly carried out a T-test analysis on the raw data earlier this year. Her findings were even more dramatic than my untrained eye had guesstimated
I shall now try my damnedest to present this vast number of statistics in a manner that is not only digestible but interesting"...


In 2022, Sally Cat also created a PDA Bingo resource which was drawn largely from PDA traits highlighted in this study. This resource isn't a clinical tool but illustrates many PDA traits people might recognise. Please note, traits may not be present for every PDA person.