For those new to DQ3, the game starts off with a personality quiz which will determine your character's stats.
It should also be stated that some personalities such as the Vamp personality are female only.
Below is an image with the required answers to get the personality you wish. (credits to game8.co for the image)

• Acrobat - Agility increases quickly.
  
  
• Aristocrat - Luck increases extremely quickly, Wisdom increases slightly quicker, Resilience increases slowly.
  
  
• Bat out of Hell - Agility increases extremely quickly.
  
  
• Bodybuilder - Strength increases extremely quickly, Resilience increases slightly quicker.
  
  
• Charmer - Stamina and Strength increase quickly.
  
  
• Clown - Agility increases quickly, Wisdom and Luck increase slightly quicker.
  
  
• Contrarian - Luck increases extremely quickly, Agility increases quickly, Strength and Stamina increase slowly.
  
  
• Crybaby - Luck increases quickly, Wisdom increases slightly quicker, Resilience increases slowly.
  
  
• Daredevil - Agility and Stamina increase quickly, Resilience increases slowly.
  
  
• Daydreamer - Agility and Wisdom increase slightly quicker.
  
  
• Drudge - Strength increases quickly, Resilience and Stamina increase slightly quicker.
  
  
• Egghead - Wisdom increases quickly, Resilience increases slightly quicker.
  
  
• Everyman - Every stat increases evenly.
  
  
• Free Spirit - Resilience and Stamina increase slightly quicker, Agility increases slowly.
  
  
• Genius - Wisdom increases extremely quickly, agility increases quickly.
  
  
• Good Egg - All stats increase evenly.
  
  
• Gourmand - Resilience increases extremely quickly, Strength and Stamina increase slightly quicker, Wisdom and Agility increase slowly.
  
  
• Happy Camper - Luck increases extremely quickly.
  
  
• Idealist - Resilience and Strength increase quickly, Luck increases slowly.
  
  
• Ironclad - Resilience and Stamina increase extremely quickly.
  
  
• Klutz - Agility increases quickly, Wisdom and Luck increase slowly.
  
  
• Lazybones - Stamina increases quickly, Luck increases slightly quicker, Resilience and Wisdom increase slowly.
  
  
• Lone Wolf - Resilience and Stamina increase quickly, Luck increases slowly.
  
  
• Lout - Luck increases slightly quicker, Wisdom increases slowly.
  
  
• Lucky Devil - Luck increases extremely quickly, Agility increases slightly quicker.
  
  
• Meathead - Strength increases extremely quickly, Wisdom increases slowly.
  
  
• Meddler - Stamina increases slightly quicker.
  
  
• Mule - Resilience and Stamina increase quickly, Wisdom, Agility, and Luck increase slowly.
  
  
• Narcissist - Agility increases slightly quicker.
  
  
• Paper Tiger - Stamina increases quickly.
  
  
• Paragon - Strength increases extremely quickly, Agility, Wisdom, and Luck increase slowly.
  
  
• Plugger - Resilience and Stamina increase quickly, Luck increases slowly.
  
  
• Scatterbrain - Agility increases quickly.
  
  
• Shrinking Violet - Stamina increases quickly, Wisdom increases slightly quicker, Agility increases slowly.
  
  
• Show-Off - Strength, Resilience, and Agility increase slightly quicker.
  
  
• Slippery Devil - Wisdom increases quickly, Resilience and Agility increase slightly quicker.
  
  
• Socialite - Wisdom and Luck increase slightly quicker.
  
  
• Sore Loser - Agility and Stamina increase slightly quicker.
  
  
• Spoilt Brat - Luck increases slightly quicker.
  
  
• Straight Arrow - Stats increase evenly.
  
  
• Tear-Away - Strength and Agility increase quickly.
  
  
• Thug - Strength increases quickly, Resilience increases slightly quicker, Wisdom and Luck increase slowly.
  
  
• Tough Cookie - Stamina and Resilience increase extremely quickly, Luck increases slowly.
  
  
• Wimp - Wisdom and Luck increase quickly, Agility increases slowly.
  
  
• Wit - Wisdom increases extremely quickly.
  
  
• Vamp - Agility and Luck increase quickly, other stats increase evenly.

Thanks for reading the guide! If you found it helpful please consider rating/favoriting it!
Lastly if theres anything else that you think I should add feel free to mention it in the comments!