diff --git a/reasoning_gym/graphs/family_relationships.py b/reasoning_gym/graphs/family_relationships.py
index 18ebd713..9a6ba7fa 100644
--- a/reasoning_gym/graphs/family_relationships.py
+++ b/reasoning_gym/graphs/family_relationships.py
@@ -1,8 +1,8 @@
 import random
-import uuid
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from typing import Optional, Dict, List, Set, Tuple
 from enum import Enum
+from itertools import count
 
 from ..dataset import ProceduralDataset
 
@@ -29,22 +29,22 @@ class Relationship(Enum):
 class Person:
     name: str
     gender: Gender
+    id: int
     spouse: Optional['Person'] = None
     parents: List['Person'] = None
     children: List['Person'] = None
-    _id: uuid.UUID = field(default_factory=uuid.uuid4, compare=False)
 
     def __post_init__(self):
         self.parents = self.parents or []
         self.children = self.children or []
 
     def __hash__(self):
-        return hash(self._id)
+        return self.id
 
     def __eq__(self, other):
         if not isinstance(other, Person):
             return False
-        return self._id == other._id
+        return self.id == other.id
 
     def add_child(self, child: 'Person'):
         if child not in self.children:
@@ -149,15 +149,18 @@ class FamilyRelationshipsDataset(ProceduralDataset):
             used_names.add(name)
             return name
 
+        # Create ID counter
+        id_counter = count()
+        
         # Create grandparents generation
-        grandfather = Person(get_name(Gender.MALE), Gender.MALE)
-        grandmother = Person(get_name(Gender.FEMALE), Gender.FEMALE)
+        grandfather = Person(get_name(Gender.MALE), Gender.MALE, next(id_counter))
+        grandmother = Person(get_name(Gender.FEMALE), Gender.FEMALE, next(id_counter))
         grandfather.add_spouse(grandmother)
         family.update([grandfather, grandmother])
 
         # Create parents
-        father = Person(get_name(Gender.MALE), Gender.MALE)
-        mother = Person(get_name(Gender.FEMALE), Gender.FEMALE)
+        father = Person(get_name(Gender.MALE), Gender.MALE, next(id_counter))
+        mother = Person(get_name(Gender.FEMALE), Gender.FEMALE, next(id_counter))
         father.add_spouse(mother)
         grandfather.add_child(father)
         grandmother.add_child(father)
@@ -169,7 +172,7 @@ class FamilyRelationshipsDataset(ProceduralDataset):
             name = get_name(gender)
             if not name:
                 break
-            child = Person(name, gender)
+            child = Person(name, gender, next(id_counter))
             father.add_child(child)
             mother.add_child(child)
             family.add(child)