WHEN it comes to long-term planning, politicians and adolescents have something in common: they aren’t wired to do it well.

The first group must try to balance two aims: to transform society for the better and to win the next election. If the strategy for the latter fails, then the former won’t be possible, but if all the focus is on short-term electoral strategy, the result will be incremental progress at best, and stagnation at worst.

The second group must try to weigh up the chance for a quick dopamine hit against potential negative impacts of risk-taking or otherwise short-sighted behaviour – which could range from a fall-out with a pal right up to a criminal prosecution.

The latest evidence suggests that the brain development necessary to do this well is not complete until at least the age of 25. It’s for this reason that the Scottish Sentencing Council has introduced specific guidelines relating to young offenders.

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Of course, not everyone agrees that under-25s should face softer sentences purely because of their age or maturity level. But those who accept the evidence when it relates to offending adolescents tend not to bring it up when discussing, for example, whether those aged 16 and 17 should have the vote.

Instead, we hear that because young people can do “adult” things like joining the army or getting married, they should be entitled to their say (it’s worth noting that under-18s cannot vote in England, but these days they also cannot get married).

The last few weeks have been an emotional time for SNP members, who first received the shock news that Nicola Sturgeon was resigning and then looked on as the battle to replace her erupted into yellow-on-yellow clashes on live TV followed by public challenges to the party’s high heid yins, the disclosure – at a time of maximum impact – of the loss of tens of thousands of members and a flurry of resignations that left even party president Mike Russell admitting the whole situation was a “tremendous mess”.

Reading the letters submitted to The National by veteran Yessers – some SNP members, some supporters, some members and supporters of other pro-indy parties – the prevailing mood is one of sadness, dismay and anxiety about what the current circus means for the party’s future and above all for the cause of independence.

However, reading tweets, columns and comments by younger Yes supporters, the prevailing emotions are defensiveness (of the party, and more importantly of their morally superior in-group) and outrage at the very prospect that someone they disapprove of might become the new first minister.

To call them “Yes supporters” is perhaps questionable, given their status as such may be conditional on events unfolding in a particular way over the next few weeks. They might not say so outright, but there’s a very strong hint of “nice set of youth Yes voters you’ve got here ... shame if anything were to happen to them...”

Tantrum would perhaps be too strong a word at this stage, but all of this is happening before the result of the leadership contest has been announced.

The SNP must accept some responsibility for the fact that certain sectors of their membership (and plenty of non-member activists) have little experience of being told “no” – or even “there’s a policy process that must be followed”. If Monday’s result triggers a mass dummy-spitting, I certainly wouldn’t want to be downwind of it.

The SNP members who have been around the block a few times, experiencing highs as well as lows, are concerned about the fall in membership and the possibility that younger people – including their own children and grandchildren – may become politically disengaged.

By contrast, younger activists who have experienced nothing but electoral success for the SNP have no qualms about hectoring, lecturing and scolding their elders for their supposedly intolerable values and priorities, stoking intergenerational conflict in the same breath as they chastise Kate Forbes for giving the opposition ammunition.

It is claimed by some that members have deserted the SNP due to the party’s refusal to listen to concerns about the Gender Recognition Reform Bill, but in truth we don’t know what explains the drop.

Given the party’s raison d’etre is restoring Scotland’s independence, it’s not unreasonable to conclude that a lack of progress on that front has left many deflated and demotivated.

There is perhaps a degree of projection from those who assume anyone departing has stropped off. It’s easier to lash out with a petulant “good riddance!” than to ask careful questions about how best to talk round those who have let their membership lapse.

The new leader will presumably endeavour to find out why so many members left. Perhaps some are the young people who Mhairi Black claims have had their “enthusiasm knocked out of them” by older branch members. Perhaps some are women of all ages who objected to being called “Jeremy Hunts” by the very same Mhairi Black. There’s no one-size-fits-all approach that will lure both groups back.