The difference between someone with an IQ of 115 and someone with an IQ of 175 is four standard deviations. Four standard deviations is huge. It is equal to the difference between a PhD in science and someone hovering on the edge of an intellectual disability.
I’d be careful with this kind of comparison. IQ numbers and SDs may look like cardinal measurements, but they’re actually an ordinal hierarchical system. What one can say is that someone with IQ n+1 is “smarter than” someone with IQ n, who in turn is “smarter than” someone with IQ n-1. But there’s no way, for now, to convert that in a cardinality.
Hence, in an absolute sense of literal, actual intelligence, the difference in between an IQ 175 and an IQ 115 may be either greater or smaller than the difference in intelligence between an IQ 115 and an IQ 55. My personal hunch is that it’s much smaller, although, evidently, I have no way to back that up.
I’d be careful with this kind of comparison. IQ numbers and SDs may look like cardinal measurements, but they’re actually an ordinal hierarchical system. What one can say is that someone with IQ n+1 is “smarter than” someone with IQ n, who in turn is “smarter than” someone with IQ n-1. But there’s no way, for now, to convert that in a cardinality.
Hence, in an absolute sense of literal, actual intelligence, the difference in between an IQ 175 and an IQ 115 may be either greater or smaller than the difference in intelligence between an IQ 115 and an IQ 55. My personal hunch is that it’s much smaller, although, evidently, I have no way to back that up.