diff --git a/psyneulink/core/components/component.py b/psyneulink/core/components/component.py
index 5c2f4175016..13756416e48 100644
--- a/psyneulink/core/components/component.py
+++ b/psyneulink/core/components/component.py
@@ -2167,13 +2167,10 @@ def _initialize_parameters(self, context=None, **param_defaults):
         alias_names = {p.name for p in self.class_parameters if isinstance(p, ParameterAlias)}
 
         self.parameters = self.Parameters(owner=self, parent=self.class_parameters)
+        self.defaults = Defaults(owner=self, parent=self.class_defaults)
 
         # assign defaults based on pass in params and class defaults
-        defaults = {
-            k: v for (k, v) in self.class_defaults.values(show_all=True).items()
-            if k not in alias_names
-        }
-
+        defaults = {}
         if param_defaults is not None:
             for name, value in copy.copy(param_defaults).items():
                 if name in alias_names:
@@ -2214,13 +2211,14 @@ def _initialize_parameters(self, context=None, **param_defaults):
         for k in defaults:
             if defaults[k] is None:
                 continue
-            defaults[k] = copy_parameter_value(
-                defaults[k],
-                shared_types=shared_types
+            setattr(
+                self.defaults, k,
+                copy_parameter_value(
+                    defaults[k],
+                    shared_types=shared_types
+                )
             )
 
-        self.defaults = Defaults(owner=self, **defaults)
-
         for p in filter(lambda x: not isinstance(x, (ParameterAlias, SharedParameter)), self.parameters._in_dependency_order):
             # copy spec so it is not overwritten later
             # TODO: check if this is necessary
diff --git a/psyneulink/core/globals/parameters.py b/psyneulink/core/globals/parameters.py
index 49d8fd9c11a..ed776573685 100644
--- a/psyneulink/core/globals/parameters.py
+++ b/psyneulink/core/globals/parameters.py
@@ -978,7 +978,7 @@ def __init__(
         reference=False,
         dependencies=None,
         initializer=None,
-        port=None,
+        port=None,  # if modulated, set to the ParameterPort
         mdf_name=None,
         specify_none=False,
         _owner=None,
@@ -988,7 +988,6 @@ def __init__(
         # attributes will be taken from
         _inherited_source=None,
         _user_specified=False,
-        # if modulated, set to the ParameterPort
         **kwargs
     ):
         if isinstance(aliases, str):
@@ -1246,7 +1245,7 @@ def _restore_inherited_attrs(self, exclusions=None):
                 attr not in exclusions
                 and getattr(self, attr) is getattr(self._parent, attr)
             ):
-                setattr(self, attr, self._inherited_attrs_cache[attr])
+                super().__setattr__(attr, self._inherited_attrs_cache[attr])
 
     @property
     def _parent(self):
@@ -1726,9 +1725,10 @@ def _initialize_from_context(self, context=None, base_context=Context(execution_
     # KDM 7/30/18: the below is weird like this in order to use this like a property, but also include it
     # in the interface for user simplicity: that is, inheritable (by this Parameter's children or from its parent),
     # visible in a Parameter's repr, and easily settable by the user
-    def _set_default_value(self, value):
-        value = self._parse(value)
-        self._validate(value)
+    def _set_default_value(self, value, directly=False):
+        if not directly:
+            value = self._parse(value)
+            self._validate(value)
 
         super().__setattr__('default_value', value)
 
@@ -2174,8 +2174,11 @@ def __setattr__(self, attr, value):
             super().__setattr__(attr, value)
         else:
             if isinstance(value, Parameter):
+                is_new_parameter = False
+
                 if value._owner is None:
                     value._owner = self
+                    is_new_parameter = True
                 elif value._owner is not self and self._initializing:
                     # case where no Parameters class defined on subclass
                     # but default value overridden in __init__
@@ -2186,7 +2189,8 @@ def __setattr__(self, attr, value):
                     value.name = attr
 
                 if self._initializing and not value._inherited:
-                    value.default_value = self._reconcile_value_with_init_default(attr, value.default_value)
+                    reconciled_value = self._reconcile_value_with_init_default(attr, value.default_value)
+                    value._set_default_value(reconciled_value, directly=not is_new_parameter)
 
                 super().__setattr__(attr, value)