It　may　be　only　a　temporary　phase　of　their　lives；　but　while　it　lasts　it　is　very　troublesome。　In　E。's　case　the　overexcitable　hypokinetic　stage　lasted　until　about　the　ninth　year；　and　then　there　was　a　great　improvement；　though　he　still　was　of　the　same　general　type。　He　became　a　fairly　good　runner　for　a　short　distance；　learned　to　swim；　though　he　stood　the　cold　water　poorly；　was　clever　and　graceful　as　a　dancer　and　was　quite　popular。　At　sixteen　he　left　school　to　enter　business；　because　of　the　straitened　means　of　his　family。　He　entered　into　adolescent　period　later　and　suffered　greatly　from　his　sixteenth　to　nineteenth　year　from；　fatigue；　hypochondriacal　fears；　and　had　to　have　a　good　deal　of　medical　attention　at　this　time。　Sex　questions　perplexed　him；　for　he　became　quite　passionate　and　at　the　same　time　had　much　moral　repugnance　to　illicit　relations。　His　sexual　curiosity　was　intense；　and　he　read　all　manner　of　books　on　the　subject；　went　to　the　burlesque　shows　on　the　sly　and　almost　became　obsessed　on　sex　matters。　At　this　stage　he　made　only　a　mediocre　showing　in　his　business　career；　though　his　evident　honesty　secured　him　promotion　to　a　clerk's　position。　After　his　nineteenth　year　he　seemed　to　gain　again　in　energy　and　endurance　and　was　fairly　well　until　his　twenty…eighth　year；　though　he　had　to　nurse　his　endurance　at　all　times；　developed　very　regular　habits　of　sleep；　diet；　etc。；　and　in　this　manner　got　along。　Once　he　had　an　opportunity　to　join　an　organization　which　would　have　paid　him　a　better　salary；　but　the　hours　were　irregular；　and　it　would　have　demanded　much　exertion　and　excitement；　so　he　passed　it　by。　In　1917　he　joined　the　army；　partly　because　of　patriotic　motives；　partly　because　he　was　convinced　that　army　life　might　develop　his　endurance　and　energy。　He　was　sent　to　an　army　post　in　the　South　and　within　two　months　of　his　entrance　had　〃broken　down。〃　He　was　sleepless；　restless；　was　irritable　and　〃jumpy；〃　had　lost　appetite　and　the　feeling　of　endurance。　Life　seemed　intolerable；　though　he　had　no　desire　to　do　away　with　himself；　for　he　had　no　quarrel　with　life　itself　but　was　disgusted　with　his　inferiority。　He　was　hospitalized；　but　this　did　little　good　and　he　was　afterwards　discharged　as　medically　unfit。　This；　of　course；　hurt　his　pride；　but　essentially　he　was　greatly　relieved。　He　made　but　slow　improvement　until　through　the　munificence　of　Uncle　Sam　he　was　given　a　new　start　in　life　through　the　Vocational　Reeducation　Board。　Like　many　other　city　men；　he　has　dreamed　of　the　〃chicken　farm〃　as　the　ideal　occupation　free　from　too　much　work　and　yet　lucrative。　This；　of　course；　is　a　mistaken　notion；　but　while　learning　the　work　he　is　happy　and　is　slowly　regaining　his　energy。　What　time　will　bring　forth　no　one　can　tell；　but　this　is　certain：　throughout　his　life　he　will　have　to　rely　on　good　habits；　carefully　adjusted　to　his　energy；　in　order　to　protect　himself　from　the　bankruptcy　that　so　easily　comes　on　him。　A　philosophy　of　life　which　will　help　to　control　his　irritability　is　necessary；　and　the　intelligent　of　the　hypokinetic　irritable　acquire　the　habits　and　the　philosophy　necessary　for　their　welfare。　Any　neurologist　could　cite　any　number　of　such　cases　with　varying　traits　of　character；　high　intelligence　or　feeble…minded；　controlled　in　morals　or　uncontrolled；　happily　or　unhappily　situated；　whose　central　difficulty　is　an　irritable　and　easily　exhausted　store　of　energy。　They　are　easily　excited　and　excitement　burns　them　out；　that　is　the　long　and　short　of　their　situation。　Sex；　love；　hatred；　anger；　strain；　fear　in　all　its　forms；　illness；all　these　and　many　other　emotions　and　happenings　may　break　them　down。　Such　people；　and　those　who　care　for　them；　must　not　make　the　mistake　of　thinking　that　rough　handling；　strenuosity；　will　cure　what　is　apparently　a　fixed　character。　There　is　an　irritable；　high…energy　typeirritable　hyperkineticthat　is　well　contrasted　with　the　foregoing。　This　explosive　personality　works　by　fits　and　starts　but　does　not　wear　out；　merely；　as　it　were；　settles　down　to　his　ordinary　pace　when　he　rests　up。　He　is　like　a　six…day　bicycle　racer　who　plugs　along　but　every　now　and　then　sprints　like　mad　for　a　few　laps　and　then　comes　back　to　a　pace　that　would　kill　the　average　rider。　I　shall　not　trouble　to　cite　such　a　case；　but　I　can　think　of　at　least　one　man　of　good　attainments　who　is　of　this　explosive　hyperkinetic　type。　He　responds　to　every　demand　with　a　burst　of　energy；　and　his　quota　of　ordinary　activities　is　simply　appalling。　Neglecting　the　further　types　of　energy　display　for　the　simple　reason　that　this　quality　shades　off　into　every　conceivable　type　and　is　also　a　part　of　every　nature；　we　turn　to　the　types　of　emotional　mood　display。　With　these　it　is　necessary　to　consider　excitability　as　well；　and　the　most　interesting　beings　are　here　our　objects　of　study。　I　wish　first　to　emphasize　my　belief　that　where　there　is　a　great　natural　variation　in　excitability　and　emotionality　in　individuals；　there　is　not　nearly　so　much　in　races　as　we　think；　and　that　social　heredity　is　tradition　and　cultural　level　plays　the　more　important　role　in　this。　My　friend　and　colleague；　Dr。　A。　Warren　Stearns；　has　made　a　study　which　shows　that　while　the　immigrant　Italian　is　excitable　and　quick　to　anger　and　of　revengeful　reactions；　his　American…born　descendent　has　so　far　controlled　and　changed　this　type　of　reaction　that　he　does　not　especially　figure　in　police　records；　in　murders　or　assaults。　My　own　studies　of　the　second　and　especially　the　third　generation　Jew　show　there　is　an　almost　complete　approach　to　the　〃American〃　type　in　emotional　display；　in　what　is　known　as　poise。　This　third　generation　Jewish…American　has　dropped　all　the　mannerisms　of　excitability　in　gesture　and　voice；　and　his　adherence　to　good　form　includes　that　attitude　of　nonchalant　humor　so　characteristic　of　the　American。　1。　The　generally　excitable；　overemotional　type。　This　type　is　more　common　in　the　Latin；　Hebrew　and　Celtic　races。　In　some　respects　it　corresponds　to　the　hypokinetic　irritable；　but　it　is　not　necessarily　hypokinetic。　The　artistic　type　of　person；　so　called；　is　of　this　group；　but　is；　of　course；　talented　as　well。　Talent　need　not　be　present；　and　there　are　persons　of　no　artistic　ability　whatever　who　show　a　generalized；　excitable…emotional　temperament。　All　young　children　show　the　main　traits　of　this　type；　and　there　is　something　essentially　simple　about　all　these　folk；　no　matter　how　civilized　or　sophisticated　they　get　to　be。　A。　L。；　a　woman　of　fifty；　belongs　to　this　group。　She　is　a　Jewess　and　now　a　widow。　All　of　her　life　her　character　and　temperament　have　been　the　same；　and　though　her　experiences　have　been　varied　she　has　not　in　any　essential　altered。　This　last　is　rather　characteristic　of　the　group；　for　experience　has　but　little　effect　on　their　emotional　reactions。　A。　L。　cries　very　easily　and　readily；　but　her　tears　are　easily　dried　and　her　joy　is　grotesquely　childlike。　She　is　readily　frightened；　worries　without　restraint　and　finds　a　melancholy　satisfaction　in　the　worst。　At　the　same　time；　her　fears　do　not　persist　and　are　easily　dissipated　by　encouragement　or　good　fortune。　She　is　readily　angered　and　〃raises　a　row〃　with　great　facility　and　without　restraint。　For　this　reason　her　relatives　and　friends　become　panic…stricken　when　she　becomes　angry；　for　they　know　that　she　does　not　hesitate　to　make　an　embarrassing　scene。　In　the　efforts　to　conciliate　her　they　are　apt　to　give　her　her　own　way；　as　a　result　of　which　she　is　the　proverbial　spoiled　child；　capitalizing　her　weakness。　Our　Jewess　uses　her　emotions　for　effect；　which　means　that　she　has　become　theatrical。　Though　there　is　reality　in　her　emotional　display；　time　and　the　advantages　she　has　gained　have　brought　enough　finish　and　restraint　to　her　manifestations　to　gain　the　designation　artistic。　True；　it　is　a　crude　artistry；　for　intelligence　does　not　sufficiently　guide　it；　and　her　art　is　used　sometimes　indiscriminately　and　inopportunely。　As　she　grows　older　the　value　of　her　tears　is　less；　and　she　is　becoming　that　prime　nuisance；　the　elderly　scold。　Among　the　emotional　types　well　recognized　by　the　neurologist　is　that　known　as　the　cyclothymic。　In　the　individuals　of　this　group　there　is　a　periodicity　to　mood　（rather　than　to　emotions）。　There　is　a　definitely　pathological　trend　to　the　cyclothymic；　and　in　its　most　marked　form　one　sees　the　recurring　depressions　and　excitement　of　Manic　Depressive　Insanity。　Aside　from　these　pathological　forms；　there　are　persons　who　show　curious　periodic　changes　in　mood。　They　become　depressed　for　no　especial　reason；　are　〃blue〃　for　day　after　day　and　then　quickly　return　to　their　normal。　Sometimes　these　blue　spells　alternate　with　periods　of　exaltation　and　happiness；　but　in　my　experience　this　is　far　less　common　than　periodic　blue　spells；　a　kind　of　recurrent　anhedonia。　L。　D。　is　ordinarily　what　is　known　as　a　vivacious　person。　Bright；　talkative；　keen　in　her　discriminations；　she　has　all　her　life　been　at　the　mercy　of　strange　alterations　in　mood；　alterations　which　come　and　go　without　what　seems　to　others　adequate　reason。　As　a　child　L。　D。　was　sick　a　great　deal。　She　showed　an　unusual　susceptibility　to　infection；　and　it　was　not　until　she　was　nine　years　of　age　that　she　attended　school　regularly。　Her　illnesses　made　it　impossible　to　discipline　her；　and　so　she　has　always　been　a　bit　〃spoiled；〃　though　her　kind　and　generous　natur