It would be more accurate to say that "Psychology is not 'just' a science." There are areas of psychology that rely on methods that are not scientific, because

It would be more accurate to say that "Psychology is not 'just' a science." There are areas of psychology that rely on methods that are not scientific, because their subject of study is too hard to approach in a rigorously scientific way (though that doesn't mean it's not legitimate knowledge creation, it just comes with more caveats). But there are also areas of psychology that can be, and are studied with scientific rigour, such as with similar experimental designs to biology. As someone who has formally studied psychology, the main impression this article makes is that the author knows very little about the contemporary academic discipline of psychology, and is just a bit arrogant about it.