This is how I tweaked it in my modmod:Autobuilding like barbarian culture effect, that would produce +1 culture would be better - you can play with no traits option altogether after all.
Spoiler Cultures_CIV4BuildingInfos.xml :
Code:
<BuildingInfo>
<!-- NPC Culture Barbarian -->
<BuildingClass>BUILDINGCLASS_CULTURE_NATIVE</BuildingClass>
<Type>BUILDING_CULTURE_NPC_BARBARIAN</Type>
<Description>TXT_KEY_BUILDING_CULTURE_BARBARIAN</Description>
<Civilopedia>TXT_KEY_BUILDING_CULTURE_NATIVE_PEDIA</Civilopedia>
<ArtDefineTag>ART_DEF_BUILDING_CULTURE_BARBARIAN</ArtDefineTag>
<!-- Construction cost -->
<iCost>-1</iCost>
<bAutoBuild>1</bAutoBuild>
<!-- Main effects -->
<iHealth>2</iHealth>
<iHappiness>2</iHappiness>
<CommerceChanges>
<iCommerce>0</iCommerce>
<iCommerce>0</iCommerce>
<iCommerce>1</iCommerce>
</CommerceChanges>
<CommerceModifiers>
<iCommerce>0</iCommerce>
<iCommerce>0</iCommerce>
<iCommerce>100</iCommerce>
</CommerceModifiers>
<!-- Misc. Effects -->
<iPopulationgrowthratepercentage>-25</iPopulationgrowthratepercentage>
<iMilitaryProductionModifier>25</iMilitaryProductionModifier>
<!-- Special properties -->
<bNukeImmune>1</bNukeImmune>
<iMinAreaSize>-1</iMinAreaSize>
</BuildingInfo>
<BuildingInfo>
<!-- NPC Neanderthal Culture -->
<BuildingClass>BUILDINGCLASS_CULTURE_NATIVE</BuildingClass>
<Type>BUILDING_CULTURE_NPC_NEANDERTHAL</Type>
<EnabledCivilizationTypes>
<EnabledCivilizationType>
<CivilizationType>CIVILIZATION_NPC_NEANDERTHAL</CivilizationType>
</EnabledCivilizationType>
</EnabledCivilizationTypes>
<Description>TXT_KEY_BUILDING_CULTURE_NATIVE_NEANDERTHAL</Description>
<Civilopedia>TXT_KEY_BUILDING_CULTURE_NATIVE_PEDIA</Civilopedia>
<ArtDefineTag>ART_DEF_BUILDING_NEANDERTHAL_EMBASSY</ArtDefineTag>
<!-- Prerequisites -->
<MapCategoryTypes>
<MapCategoryType>MAPCATEGORY_EARTH</MapCategoryType>
</MapCategoryTypes>
<!-- Construction cost -->
<iCost>-1</iCost>
<bAutoBuild>1</bAutoBuild>
<!-- Main effects -->
<iHealth>2</iHealth>
<iHappiness>2</iHappiness>
<CommerceChanges>
<iCommerce>0</iCommerce>
<iCommerce>0</iCommerce>
<iCommerce>3</iCommerce>
</CommerceChanges>
<CommerceModifiers>
<iCommerce>0</iCommerce>
<iCommerce>0</iCommerce>
<iCommerce>25</iCommerce>
</CommerceModifiers>
<FreeBuilding>BUILDINGCLASS_CULTURE_ACTIVE_NEANDERTHAL</FreeBuilding>
<!-- Misc. -->
<iPopulationgrowthratepercentage>-25</iPopulationgrowthratepercentage>
<iMilitaryProductionModifier>25</iMilitaryProductionModifier>
<!-- Special properties -->
<bNukeImmune>1</bNukeImmune>
<iMinAreaSize>-1</iMinAreaSize>
</BuildingInfo>