There are a number of ways a player may increase their Primary attributes, otherwise known as S.P.E.C.I.A.L. stats.
1) Intense Training
2) Bobbleheads
3) Implants
4) Items
1) A player may select Intense Training once per S.P.E.C.I.A.L. stat to increase it by +1 permanently. (ex. You can select Intense Training once for Strength, once for Perception, etc.)
2) On the West Coast of California there are 7 bobbleheads, one for each S.P.E.C.I.A.L. stat. If a player finds it they raise that stat by +1 permanently. (Bobbleheads are landmarks that remain in place. Their influence is an enigma...)
3) If a player finds the means of acquiring one of these they may do so up to their Implant Endurance. (=EN)
4) Sometimes clothes, armour, or other AID items will provide a temporary bonus to a player's SPECIAL stats.