 He said that when needs in a higher category are not met then individuals redouble the efforts invested in a lower category need .
<clarity>  He said that when needs in a higher category are not met then individuals redouble the efforts invested in a lower category need .
 He said that when needs in a lower category are satisfied, individuals invest more efforts in the higher category, and when needs in a higher category are frustrated, individuals invest more efforts in the lower category .