In the SRD it states:
Ability Score Improvement
Treat monster Hit Dice the same as character level for determining ability score increases. This only applies to Hit Dice increases, monsters do not gain ability score increases for levels they "already reached" with their racial Hit Dice, since these adjustments are included in their basic ability scores.
Meaning that for every 4 hit dice a monster has it gains an ability score improvement of +1 on any one ability score. In the SRD in the monster entry for Lycanthrope under abilities section of the Creating a lycanthrope subsection is stated this:
All lycanthropes gain +2 to Wisdom. In addition, when in animal form, a lycanthrope’s physical ability scores improve according to its kind, as set out in the table below. These adjustments are equal to the animal’s normal ability scores -10 or -11. A lycanthrope in hybrid form modifies its physical ability scores by the same amount. In addition, a lycanthrope may also gain an additional ability score increase by virtue of its extra Hit Dice.
A werebear in human form has the following stats:
Str 13, Dex 11, Con 12, Int 10, Wis 11, Cha 8
And is based upon:
The werebear presented here is a 1st-level human warrior and natural lycanthrope, using the following base ability scores: Str 13, Dex 11, Con 12, Int 10, Wis 9, Cha 8.
Otherwise known as the 'non elite array' or 'low powered campaign / 15 point buy'
The +2 increase to wisdom is the Wisdom bonus that a lycanthrope receives. Where is the +1 ability score increase to a stat from having 4 or more HD? As the statement '...monsters do not gain ability score increases for levels they "already reached" with their racial Hit Dice, since these adjustments are included in their basic ability scores.' seems to be incorrect because the adjustment has not been included.
Is this a mistake or something I am missing? Incidentally I have checked Cooper’s Compendium Of Corrected Creatures and no mention of this seeming discrepancy may be found in that source which makes me question whether it's something I've forgotten?
Further research of this problem indicates it isn't just constrained to lycanthropes take the Hound Archon Hero for example:
Page 6 & 7 of the Monster Manual inform that:
Advanced creatures such as the hound archon hero are built using the elite array: 15, 14, 13, 12, 10, 8.
The ability scores of the hound archon hero are: Str 21, Dex 10, Con 16, Int 8, Wis 14, Cha 16
If the racial ability score modifiers (+4 Strength, +2 Constitution, +2 Wisdom, +2 Charisma) are deducted leaves: Str 17, Dex 10, Con 14, Int 8, Wis 12, Cha 14.
How were these scores arrived at from the elite array 15, 14, 13, 12, 10, 8? The only possible way this was done was if the total ability score increase from class and HD was +3.
Str 15, Dex 10, Con 13, Int 8, Wis 12, Cha 14 with ability score increases of +2 Str and +1 Con.
This has been calculated by taking 6 Racial HD adjusting an ability score by +1 for the increase at 4 Racial HD and then taking 11 class levels of paladin adjusting ability scores by +2 for the class ability score adjustments at 4 and 8 class levels.
Because there is no other way of arriving at those totals this demonstrates that both racial hit dice and class levels comprise the calculation to adjust ability scores. However this then would still be incorrect because a 17 HD creature (6 Racial HD + 11 paladin class levels) should receive a +4 total ability score adjustment.
I believe the error is in that Racial HD and Paladin levels were calculated independent of one another for ability score adjustments.