diff --git a/django/contrib/admin/validation.py b/django/contrib/admin/validation.py
index 63be20f504..ccade8a3ef 100644
--- a/django/contrib/admin/validation.py
+++ b/django/contrib/admin/validation.py
@@ -36,6 +36,8 @@ def validate(cls, model):
                         except models.FieldDoesNotExist:
                             raise ImproperlyConfigured("%s.list_display[%d], %r is not a callable or an attribute of %r or found in the model %r."
                                 % (cls.__name__, idx, field, cls.__name__, model._meta.object_name))
+                    else:
+                        # getattr(model, field) could be an X_RelatedObjectsDescriptor
                         f = fetch_attr(cls, model, opts, "list_display[%d]" % idx, field)
                         if isinstance(f, models.ManyToManyField):
                             raise ImproperlyConfigured("'%s.list_display[%d]', '%s' is a ManyToManyField which is not supported."
diff --git a/django/contrib/contenttypes/generic.py b/django/contrib/contenttypes/generic.py
index 0504592ebb..c294f74500 100644
--- a/django/contrib/contenttypes/generic.py
+++ b/django/contrib/contenttypes/generic.py
@@ -59,7 +59,7 @@ class GenericForeignKey(object):
 
     def __get__(self, instance, instance_type=None):
         if instance is None:
-            raise AttributeError, u"%s must be accessed via instance" % self.name
+            return self
 
         try:
             return getattr(instance, self.cache_attr)
@@ -183,7 +183,7 @@ class ReverseGenericRelatedObjectsDescriptor(object):
 
     def __get__(self, instance, instance_type=None):
         if instance is None:
-            raise AttributeError, "Manager must be accessed via instance"
+            return self
 
         # This import is done here to avoid circular import importing this module
         from django.contrib.contenttypes.models import ContentType
diff --git a/django/db/models/fields/related.py b/django/db/models/fields/related.py
index c87b823a69..146a1ae457 100644
--- a/django/db/models/fields/related.py
+++ b/django/db/models/fields/related.py
@@ -175,7 +175,7 @@ class SingleRelatedObjectDescriptor(object):
 
     def __get__(self, instance, instance_type=None):
         if instance is None:
-            raise AttributeError, "%s must be accessed via instance" % self.related.opts.object_name
+            return self
 
         try:
             return getattr(instance, self.cache_name)
@@ -223,7 +223,7 @@ class ReverseSingleRelatedObjectDescriptor(object):
 
     def __get__(self, instance, instance_type=None):
         if instance is None:
-            raise AttributeError, "%s must be accessed via instance" % self.field.name
+            return self
         cache_name = self.field.get_cache_name()
         try:
             return getattr(instance, cache_name)
@@ -287,7 +287,7 @@ class ForeignRelatedObjectsDescriptor(object):
 
     def __get__(self, instance, instance_type=None):
         if instance is None:
-            raise AttributeError, "Manager must be accessed via instance"
+            return self
 
         rel_field = self.related.field
         rel_model = self.related.model
@@ -500,7 +500,7 @@ class ManyRelatedObjectsDescriptor(object):
 
     def __get__(self, instance, instance_type=None):
         if instance is None:
-            raise AttributeError, "Manager must be accessed via instance"
+            return self
 
         # Dynamically create a class that subclasses the related
         # model's default manager.
@@ -545,7 +545,7 @@ class ReverseManyRelatedObjectsDescriptor(object):
 
     def __get__(self, instance, instance_type=None):
         if instance is None:
-            raise AttributeError, "Manager must be accessed via instance"
+            return self
 
         # Dynamically create a class that subclasses the related
         # model's default manager.