The Why #75: Why do unfinished DIY projects do my head in?

4 min readNov 2, 2023


By Dan Monheit 2nd November

Question from Sam, North Melbourne

You’re not alone on this one, Sam. I imagine if I too was a DIY guy I would also be annoyed about semi-trimmed hedges, half built cubby houses and unfinished fences. Alas, I’m not. So, instead I lie in bed worrying about unanswered emails, not-quite-ready-to-give presentations and the incredible season I started on NBA2K21 that somehow got lost in a major software update.

It could just be Halloween, but it certainly feels like we’re haunted by DIY projects that never got DI-Done. Maybe it’s spooky, or maybe there’s something behavioural at play…

The Zeigarnik Effect

The Zeigarnik Effect describes how we remember incomplete, interrupted or unresolved tasks more easily than those we’ve finished. Starting a task that we’re interested in brings an overwhelming desire to complete it. This desire tends to stay with us until we do so.

To put this to the test, Bluma Zeigarnik herself ran an experiment back in 1927 to test how easily children could recall the details of tasks. Two groups were instructed to work on a series of puzzles and basic maths problems. Group One was interrupted midway through their tasks and asked to stop completely. Meanwhile, Group Two was allowed to completely finish what they were working on before being asked to leave. After an hour away from their tasks, the children were asked if they remembered what they’d done.

While 12% of the ‘completed’ group could recall the tasks in detail, this figure jumped to 80% for the ‘interrupted’ group. Evidently, the incomplete tasks were still ticking away in the minds of Group One.

This all makes complete sense when we consider that when we start and then complete a task, we’re rewarded with a dopamine hit and an accompanying sense of satisfaction. How else would we get anything done? When instead a task goes unfinished, we’re left motivated and invested in keeping it top of mind, in the hope of completing it and cashing in our mental reward.

Based on that Sam, we both know there are only three options from here. The first is to commit hard to finishing that planter box/pergola/veggie patch/whatever’s keeping you up at night, knowing there’s a big, fat dopamine hit waiting for you on the other side.

Option two is getting comfortable with the uncomfortable, knowing that for the rest of your natural life, no matter where you find yourself, you will never be able to truly relax. And then, of course, there’s option three, which is my personal favourite. It starts with ‘air’, ends with ‘tasker’ and I can assure you, will be worth every cent.

Brands can get the most out of the Zeigarnik Effect by skipping the whole story. Instead, consider providing just enough to hook your audience, safe in the knowledge that you’ll come back and close the loop down the track. Think cryptic headlines, incomplete catch phrases or a cliff hanging piece of content. Of course, you could also…

Behaviourally Yours,

Dan Monheit

PS If you missed the last edition, you can still check why we think car insurance is a no-brainer while health insurance is so-so here.

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Bad Decisions Podcast
Learn more about the Zeigarnik Effect in episode #17 of the Bad Decisions podcast.

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