Typically it tested people's knowledge of concepts like compound interest.
But Kempson said it was not clear if the tests were measuring people's maths skills or their understanding of the concept.
She said most financial literacy programmes were focused on holding workshops and telling people what they needed to know.
But psychological analysis pointed to those attempts as being a complete waste of time because people have in-built biases and human behaviours like apathy which means they just don't get around to changing their finances.
"People take short-cuts, have a desire for instant gratification and are risk averse."
Kempson said instead of literacy it was better to focus on financial capability to measure what people do with their money rather than what they know.
"People who are rainy day savers as adults were all encouraged to save as children."
But miss-selling of products and products which did not make it clear who they were suitable for could not be overcome by education.
Kempson said it should be up to the regulator to make sure products were fit for purpose.