It is a fundamental mechanism of mind, one that allows us to use what we know about our physical and social experience to provide understanding of countless other subjects say Berkeley linguist George Lakoff and the philosopher Mark Johnson at the University of Oregon in Metaphors We Live By.
Can metaphors be designed? Michael Erard in Aeon says they can.
If you could ask Dante where he got the idea of life as a road, or Rilke where he found the notion that time is a destroyer, they might have said the metaphors were hewn from their minds, or drawn from a stock of poetic imagery. Their readers might have said the imagery had origins more divine, perhaps even diabolical. But neither poets nor readers would have said the metaphors were designed. That is, the metaphors didn’t target people’s cognitive processes. They weren’t engineered to affect us in a specific way.
[...] metaphors are meant to help people to understand the unfamiliar. They aren’t supposed to make someone remark: ‘That’s beautiful.’ They’re meant to make someone realize that they’ve only been looking at one side of a thing.
Princeton psycholinguist Sam Glucksberg said metaphors are categorization proposals, provocations:
You’re suggesting that one thing belongs with another. But the thing that lets us make sense of ‘paintbrush as pump’ – or ‘lawyer as shark’ – is that ‘pump’ is the name of a category for liquid-moving mechanisms, just as ‘shark’ is the name of the category for predatory individuals. Words such as ‘pump’ and ‘shark’ aren’t just the names of individual things; they also speak to generalities. They have what Glucksberg calls ‘dual reference’. He points out others that have become conventionalized metaphors. ‘Butcher’ refers to ‘anyone who should be skilled but is incompetent’, ‘jail’ to ‘any unpleasant, confining situation’, ‘Enron’ to ‘any dramatic accounting scandal’, and ‘Vietnam’ to any ‘disastrous military intervention’.
Choreographer Twyla Tharp says comparing is the engine that drives metaphor -- this is something we can learn and train.
Psycholinguist Dedre Gentner at Northwestern University in Illinois describes metaphor as a ‘mapping’ between two concepts and understanding comes about in two steps. Whether the product of mapping or part of a metaphor category:
The designer checks out the list of conceptual metaphors that Lakoff assembled, such as ‘time is motion’, ‘states are locations’, ‘purposes are destinations’, ‘causes are physical forces’. She also collects the dual-reference terms that appear in conventional metaphors (sharks, Vietnams, jails, buildings) in order to repurpose them for new ones. You want these terms because they’re conventional and recognizable. Pipeline. Mountain. Sale.
At the same time, designers look for common conceptual domains in which analogical mappings are easy to find. There’s no dictionary of these; you have to build them yourself.
The richness of the semantic resources that a designer can muster always encounter friction from the human brain’s built-in biases and preferences, as well as cultural defaults that block certain kinds of understandings.