Personality tests have their place
The argument against Myers-Briggs personality tests is that they aren’t based on scientific evidence and so shouldn’t be used for any kind of decision-making that requires a rational basis. Deciding someone’s suitability for a job, for example, based on their Myers-Briggs Type Indicator isn’t rational and so isn’t fair to all candidates.
The same applies to ideas like creative people are right brain dominant and analytical people use their left brain more, or that people have different learning styles. They have no scientific basis and if used as if they did, could be misleading and unhelpful at best and harmful at worst.
But the point isn’t whether these things are empirically verifiable, the point is whether they have anything interesting to contribute to how we understand ourselves and relate to each other. To suggest that personality tests have nothing to contribute to discussions about people and their preferences would be like saying that poetry has nothing to contribute to our understanding about love. As with many things, it isn’t the thing itself that is at fault but how we misuse the thing.
Should we actually want to understand personality better, we could look at the current scientific thinking around the ‘big five traits‘ and the two meta-traits of stability and plasticity. This research essentially shows that personalities change over time and are due to genetic and environmental factors, and that stability is associated with protective behaviours and plasticity is connected with exploratory behaviours. Put simply, we can say that our personalities at any given time are the result of the interplay of those two motivations; to feel safe and to explore.
So what should we do with personality tests? Consider them fun conversation starters, by all means, use them as team-building exercises, like building spaghetti towers, to prompt discussion about our preferences, but not descriptive of anyone’s fixed personality.