Is it okay not to use 'than,' when I want to say 'comparison?'
"A Princeton University study found that people who worked in a clean workspace out-performed those who worked in a cluttered one because clutter pulls your attention away from your work."
This is the sentence.
I think the sentence should be "people who worked in a clean workspace out-performed THAN those who~"
Why isn't 'than' used in the sentence even though the meaning implies comparison between different people?
Thank you very much!