A two-year-old girl has officially become the youngest member of high-IQ society Mensa.Isla McNabb, a two-year-old from Crestwood, Kentucky, recently joined the organisation after scoring in the 99th percentile of intelligence for her age, according to Spectrum News.Amanda McNabb, the child’s mother, told the outlet that the toddler’s intelligence first began to present itself through an “affinity for the alphabet”.“She has always had an affinity for the alphabet, so we got her all kinds of blocks and magnets - multiple copies of the alphabet - and I would notice that the cat would have the letter C next to...