It was only after I started getting interested in intelligence research about seven years ago that I heard the phrase 'low hanging fruit' being used as an explanation.
The first time was, indeed, a suggestion that the field of intelligence research itself was full of low hanging fruit - easy pickings - because most people were too afraid to work in the field.
Since then I have been hearing the phrase more often, especially as a way of explaining why scientists in the past seem to be so much better than scientists nowadays.
The implication is that the breakthroughs of the past were more frequent because the problems were easier to solve and the answers were more obvious, whereas nowadays it is supposedly harder to make breakthroughs than in the past because the problems are much harder...
Or, to put it another way, the 'low hanging fruit' notion assumes that it is easier to make significant breakthroughs when the field is new, virgin territory, unexploited - supposedly breakthroughs are simply waiting there to be 'plucked' by the first person who stumbles upon them.
The 'low hanging fruit' argument is built on many assumptions - most of which are false.
1. That creativity is relatively common.
2. That creative ability is constant across time, place and circumstances.
3. That history is progressive (assuming that modern people and circumstances are overall 'better' than those of the past).
4. That an analogy of creativity as picking fruit makes sense.
I disagree with all of these.
To decide whether people of the past were (as people) better, worse
or the same at making creative breakthroughs it is necessary to
understand creative breakthroughs.
This means that we must study creativity - via history and biography and acquaintance with creative people - and understanding creativity requires some minimal level of creativity otherwise it could not be recognized.
But my judgement is that 1. creativity is rare - and even mundane levels of creativity are uncommon.
Furthermore, 2. there are many eras, places and circumstances when creativity is apparently absent. And 3. there is really nothing to suggest that creativity is progressive, and the amount of it accumulates through time within any culture - rather creativity seems to come in blips - in creative eras whether shorter or longer, and then may disappear.
But my major disagreement regards the nature of the creative process itself, and the cognitive difficulty of making a significant breakthrough.
Most people are not creative, and few people have struggled to solve a problem for more than a few minutes (and that includes nearly all so-called 'scientists' - who simply get their problems from other people and try to solve them by following recipes).
Experience and knowledge of creative insight and invention makes it clear that breakthroughs are very very hard to achieve.
The simplest breakthroughs (i.e. simple in retrospect) are, in fact, by far the hardest to make - as should be obvious from the fact that despite the simplicity of the solution, nobody had actually made the breakthrough!
And, the more (potentially) important the breakthrough is, the bigger the difference between the difficulty of solving the problem and the ease of understanding and using the solution.
The best and most important technological breakthroughs have often been astonishingly simple - once achieved. Things like the spade, bow and arrow, wheel, arch. We know of cultures that failed to discover these for centuries - yet as soon as they were discovered they spread 'like wildfire'.
The pattern of creativity is that it is very hard to discover things; yet sometimes very easy to understand, use and exploit them after they have been discovered.
Therefore it is clear that creative discovery is nothing like picking fruit!
Indeed, experience suggests that creative people who have themselves experienced creative science will never dismiss past breakthroughs as 'low hanging fruit'.
To regard the simple, major work of the past as akin to plucking low hanging fruit is, indeed, evidence of either an uncreative mind (such as the vast majority of people have) or a potentially creative person who has not yet actually achieved anything creative.
It is okay to speculate about whether or not major breakthroughs of the past were analogous to 'easy pickings' - a matter of scooping-up goodies that were just waiting to be gathered by the first person to stumble-upon them - but anyone informed and competent will swiftly conclude that the 'low hanging fruit' explanation is arrogant, blind, complacent, foolish nonsense.