by: WLKY, CBS Newspath Posted: Jun 28, 2022 / 10:21 PM EDT Updated: Jun 28, 2022 / 10:54 PM EDT SHARE (WLKY) – At two years old, Isla McNabb could read at a kindergarten level. A psychiatrist gave Isla an IQ test– and she scored in the 99th percentile. Now, Isla is the youngest member of MENSA, the largest and oldest high IQ society.