It's not just you.

- They found a higher rate ("almost half") of autistic children "creating imaginary friends" than prior research.

- A comparison is drawn between autistic children with imaginary friends versus autistic children without. Those with had "better social skills" than those without.

- Prior research has found a similar difference in the general population (non-autistic children).

As always, though, correlation != causation. It could well be the case that half of children (autistic or not) have some extra innate capacity for socialization, and that typical parenting choices don't provide those children as much social input as their brain wants at a certain stage of development, and hence they make up imaginary friends to interact with in order to satisfy their enhanced social needs. In other words, the imaginary friends could be an effect rather than a cause.

In context, one would expect “better than” to refer to autistic children without imaginary friends, simply because deficits in social skills are a defining feature of autism.

As such, the title is technically ambiguous but practically speaking, not.

> Is it because english isn't my first language, or is the title somewhat ambigious?

The truncated HN headline is a little ambiguous, though the most natural reading is correct; the full source title / subtitle is not ambiguous at all:

“Autistic children with imaginary friends have better social skills, just like neurotypical children / Results suggest that pretend play provides similar social benefits to autistic children as it does to neurotypical children.”

Constraints force compromise.

Better than autistic children who do not have imaginary friends. It's not said explicitly, but it's obvious, and could be used in e.g. a magazine article title without the clarification. I think it might even seem a little too "spoon-fed" if they've spelled it out...