My wife had a poor history of saving when we first met while saving and planning ahead financially are one of my strongest areas of discipline. However I think our differences were as much a function of circumstance and nurture as anything innate. Overall I think she wins hands down on discipline, intelligence and foresight vs me.

Because of this core discipline, intelligence and foresight– over time she’s moved far closer to my spending and saving habits having seen their value (and in turn I’ve loosened up, and would still acknowledge it'd probably be optimal for me to do more of that. Time and willpower are often cheaply purchased.)

Of course we have to go on the limited signals we have but remember saving is just a proxy for what we’re really after.

As an aside, I am a portfolio manager – managing circa $2bn of fixed income assets, so fees feed my family – but I wholeheartedly agree retail investors generally do much better by investing in passive funds and avoiding fees.