Added "state/psychology/cognition/GroupMembership.java"

VadereSimulator/src/org/vadere/simulator/control/psychology/cognition/ThreatCognitionModel.java

@@ -47,11 +47,15 @@ public class ThreatCognitionModel implements ICognitionModel {
                 } else {
                     // TODO: Imitate behavior if recognizing an in-group member.
                     //   Maybe, use also cooperative behavior from "CooperativeCognitionModel".
+                    // TODO: A pedestrian needs boolean variable "isInGroup" or another enum
+                    //   "Member { IN_GROUP, OUT_GROUP, OUT_GROUP_FRIENDLY, OUT_GROUP_NEUTRAL_ OUT_GROUP_HOSTILE }"
+                    //    if (pedestrian.getPerceivedThreat() != null) => These peds perceived a threat!
+                    //    else checkIfSearchRadiusContainsAThreatedPed
                     pedestrian.setSelfCategory(SelfCategory.TARGET_ORIENTED);
                 }
 
             } else {
-                throw new IllegalArgumentException("Use only \"Bang\" and \"ElapsedTime\" stimuli!");
+                throw new IllegalArgumentException("Can only process \"Bang\" and \"ElapsedTime\" stimuli!");
             }
         }
     }

VadereState/src/org/vadere/state/psychology/cognition/GroupMembership.java

+package org.vadere.state.psychology.cognition;
+
+/**
+ * According to the self-categorization theory ("reicher-2010"), people define
+ * themselves as member of social categories (see{@link SelfCategory}). When
+ * people share the same {@link SelfCategory}, they often act collectively
+ * if they feel as in-group member to this category.
+ *
+ * For instance, two protesters - which define themselves as in-group members
+ * of the category protesters - walk together during a demonstration.
+ *
+ * This enum shall capture this in- and out-group membership. The membership
+ * can be interpreted as a tree:
+ *
+ * <pre>
+ *       Membership
+ *         /\
+ *        /  \
+ *       /    \
+ *     In      Out
+ *           /  |  \
+ *          /   |   \
+ *         /    |    \
+ * Friendly  Neutral Hostile
+ * </pre>
+ *
+ * Following outcome may be observed when two people with a given membership
+ * come together:
+ * <ul>
+ *     <li>IN_GROUP / IN_GROUP => imitate behavior</li>
+ *     <li>IN_GROUP / OUT_GROUP_FRIENDLY => imitate behavior</li>
+ *     <li>IN_GROUP / OUT_GROUP_NEUTRAL => ignore behavior of IN_GROUP member</li>
+ *     <li>IN_GROUP / OUT_GROUP_HOSTILE => react hostile to IN_GROUP member</li>
+ * </ul>
+ *
+ * Note: The value "OUT_GROUP" exists for convenience if you do not like to handle
+ * the subcategories FRIENDLY, NEUTRAL and HOSTILE. "OUT_GROUP" should be handled
+ * like "OUT_GROUP_NEUTRAL". I.e., IN_GROUP / OUT_GROUP => ignore behavior of
+ * IN_GROUP member.
+ */
+public enum GroupMembership {
+    IN_GROUP,
+    OUT_GROUP,
+    OUT_GROUP_FRIENDLY,
+    OUT_GROUP_NEUTRAL,
+    OUT_GROUP_HOSTILE
+}

VadereState/src/org/vadere/state/psychology/cognition/SelfCategory.java

@@ -4,9 +4,9 @@ package org.vadere.state.psychology.cognition;
  * According to the self-categorization theory ("reicher-2010"), people define
  * themselves as member of a social category. Often, people act collectively
  * when being in the same category. E.g., protesters - which define themselves
- * as protesers - walk together during a demonstration.
+ * as protesters - walk together during a demonstration.
  *
- * Our agents can use these categorizations to to derive a specific behavior.
+ * Our agents can use these categorizations to derive a specific behavior.
  * E.g., if an agents is "COOPERATIVE", the pedestrian swaps places
  * with other "COOPERATIVE" pedestrians.
  *